# Solar fence charger for bears



## Beeter (Apr 25, 2013)

Black bears have been spotted a mile of my place. Thought that I would put up a solar fence. I was told to get a charger 4000 volt and up. Any good ideas out there where and what to get.


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## Adrian Quiney WI (Sep 14, 2007)

*Re: Solar fence sharger for bears*

One of the most popular brands i have seen mentioned in previous threads is the "Parmak"


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## drlonzo (Apr 15, 2014)

*Re: Solar fence sharger for bears*

I'm not sure of the brand, but you can find pretty good ones at the Tractor Supply stores. One major thing to remember is the length of wire that you'll be using. They state it as 1 mile, 5, 10, on the chargers. The way to know that you've sized properly is that you take the total lenght of your wire, multiply by number of strands, if using solid pig wire i'd go with the larger size.


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## Andrew Dewey (Aug 23, 2005)

*Re: Solar fence sharger for bears*

Parmak Magnum 12 - pricey but works well.


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## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*

Andrew has it spot on. When it comes to bear, you need one that is rater for at least double the distance you will be charging. In comparison to the cost Monetarily as well as psychological the cost of a quality fencer is nothing. In Pa we use fence Chargers, But I guess a sharger would work too :lpf:


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## laketrout (Mar 5, 2013)

*Re: Solar fence sharger for bears*

Stick with the parmak 12 , works great and don't forget to hang bacon or peanut butter on the fence , you want them to get zapped on the nose or tongue otherwise they will get through it.The cattle panels work very well , here is a link.

http://www.kencove.com/fence/135_Bear+Fence+-+Apiary+Fence_resource.php


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## dweber85rc (Nov 25, 2013)

*Re: Solar fence sharger for bears*

Mine isn't a solar but I have a bulldozer fencer on mine. I have one rated for 20 miles on about 20 ft of fence


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## LDuck (Apr 19, 2014)

*Re: Solar fence sharger for bears*

Highest one you can afford, tell the dealer you want it for predators. We use a plug-in model that runs an insulated cable underground from the house to the fence. It has a flashing light to let us know it is working (sweetheart, did you turn the fence back on?). We also have a solar backup (currently on loan). Consider a finer mesh fence if you've got skunks (check out Premier One supplies). We fence our whole garden to include chickens and bees; outer fence of single strand for bears & deer, inner mesh for skunks, racoon, etc. THe outer fence has 3 hot wires each within 3" of a ground wire (bridge the gap, and wow).


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## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*



laketrout said:


> Stick with the parmak 12 , works great and don't forget to hang bacon or peanut butter on the fence , you want them to get zapped on the nose or tongue otherwise they will get through it.The cattle panels work very well , here is a link.
> 
> http://www.kencove.com/fence/135_Bear+Fence+-+Apiary+Fence_resource.php


 I do not like to bait the bear to the fence. In Most cases this theory will work, however if for some reason the fences fails to get the bear, then you have successfully attracted a bear to your apiary.


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## Brad Bee (Apr 15, 2013)

*Re: Solar fence sharger for bears*



Andrew Dewey said:


> Parmak Magnum 12 - pricey but works well.


Exactly correct. While we don't have bears, we do raise cattle. We keep our own heifers as replacement stock. If a Parmak 12 will keep a bull out of the heifer pen when 20 of them are in heat, I bet it will keep a bear out of bee hives. We have 2 of those chargers and the oldest one is 10 years old and still going strong. 

If you have access to AC power, get a Zareba 100 mile AC low impedence charger. We use it on our main fence. If my wife put one of these on our refrigerator, it would keep me out of it and I would starve to death...... http://www.zarebasystems.com/store/electric-fence-chargers/eac100m-z

No DC charger will be as strong as an AC charger.


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## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

I've been told "bait the fence" and "never bait the fence".

One bit of wisdom here, somewhere, was to forget the miles of fence rating and look at the joules, the amount of energy delivered per zap. The recommendation was to get a minimum of 2 joules. I checked a couple of places including Tractor Supply and could not find a solar charger that delivers more than a fraction of a joule. I would up with a 3 joule line-powered charger, for which I will need to run power from the house, and that's probably a non-starter for 9 out of 10 apiaries.

3 joules at a pulse rate of one pulse every 1.4 seconds is 2.1 watts. But to power it with solar, I figure 4 hours of charging per 24 hours, and it must be able to handle one sunny day in 3. That means the solar charger needs to put out, in round numbers, 40 watts. That's a larger solar panel than you see on most fence chargers. You could put your own panel and battery charger on a 12 V battery ... many fence chargers are intended for a 12 V battery and you figure out how to charge it.

The most recent person to say "never bait the fence" reported on one of her fences at a recent bee club meeting. She reports piles of bear droppings about one bear length from her fence. A good fence charger DOES get their attention!


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## LDuck (Apr 19, 2014)

*Re: Solar fence sharger for bears*

a reason to bait the fence is to get the animal (bear or deer) to bridge the gap w sensitive tissue - nose or tongue - vs a calloused paw or thick fur. I don't bait but use pairs of hot & ground wires, the charge gets concentrated - or so goes the theory.

The meters used to test fences go to 7 or 8,000 volts. The charges generated have high voltage but low aperage - Amps kill - so low overall wattage. 

I've witnessed bears tangle with the fence and they work. *I* have tangled with the fence, and they work. 

Remember the first rule of electric fence maintenance - TURN OFF THE POWER.


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## Michael B (Feb 6, 2010)

*Re: Solar fence sharger for bears*

Parmak Sp12 all the way.

Fences are a deterant not a barrier. I have two SP12's and I have been very impressed with them. In the 5 years of keeping bees in various locations I have not had any bear issues. Bears have visited the yards but have been sent on thier way.

The 3.1 joule is the key. Its the power behind the shock. My fence tests between 8,600 and 9,300 volts depending on soil moisture.


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## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

My fence features grounded concrete reinforcing mesh as the physical barrier ... this is used locally in bear-resistant garbage cages, and I've seen it used as tiger enclosure fencing. Outside that are four runs of high visibility fence tape. The 3 joule charger peaks at 7.5 kV. It will throw a loud and bright 1/4" spark, visible in full daylight. I will willingly expose myself to the jolt from a smaller charger we've used for years, probably around 0.1 joules. The apiary charger, no. The 3 joule charge against a grounded fence is rated to seriously hurt.

My idea was that any bear attempting to get to the bees must come in contact with the remesh, which should be sufficient by itself. But if they keep messing with it they're bound to hit the charged tape, and which point the strong negative reinforcement should not take many repeats before they quit. One hit on the nose or mouth would also certainly be painful.


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## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*

let me see if I can help. It would take a ten page letter to explain all of the factors which make an electric shock effective. The joule does not measure the effectiveness of electric shock. The joule is a mathematical equation of Voltage x Amps x Time. The longer the" on-time" of the pulse, the higher the joule rating will be and the longer the "on-time" the less safe the fencer is to use and the less effective. The joule is not the correct way to measure the performance of any electric fence charger because the joule does not consider peak current value or "on-time" which are key factors in the effectiveness of a fencer, therefore, the joule cannot define true shock effectiveness or fencers safety. What controls livestock is voltage and amperage. You must have voltage in order to force electricity through the conductor (fence wire) as well as vegetation touching the fence, etc., and you must have current in order for the livestock to feel that shock. Joules or heat has nothing to do with it. The most effective fence charger will have the highest power (voltage and amps) possible in the shortest on-time possible, thereby allowing the fence charger to develop a sharp spike which is far more effective in controlling livestock and at the same time is safe to use. Example of how misleading the Joule rating is: The Parmak Pet Gard (model PG-50) is a continuous current, non-pulsing type charger designed for small animals in backyarcts, gardens, etc. Using the joule rating (Voltage x Amps x Time) the Pet Gard would have an unlimited joule rating making it the most powerful fencer, which it is not. In summary, it is important to point out that Underwriters Laboratories (U/L) or Canadian Standard Assoc., (CSA) do not recognize the joule as a measurement when applied to
fence charge efficiency. 

as far as baiting goes I posted my theories above, Now please allow me to elaborate with a situation that occurred last winter.

We had a big bear in the 250 pound range working the woods behind my house. he , she , it was videoed. and seem on numerous occasions throughout a very rough winter. I personally have 30 plus trail cam pictures of the bruin at less than 600 feet from my apiary, which contained 11 large hives. The fellow who own a camp on the other side of the block of woods less than 1/2 mile from me smoked some deer bologna in December. By mid January he discovered the bear had torn his shed apart to get to the smoker which had an attractive smell. I never baited the bear to my electric fence in an attempt to teach him the fence bit. I just armed it and hoped all went well. The bear never visited my apiary, and I survived the winter with all hives in tact. Now I must concede that it may have been luck. but I am a firm believer in not tempting fate.
In the end everyone must, or at least should do what they feel is best.


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## Cloverdale (Mar 26, 2012)

*Re: Solar fence sharger for bears*



Tenbears said:


> I do not like to bait the bear to the fence. In Most cases this theory will work, however if for some reason the fences fails to get the bear, then you have successfully attracted a bear to your apiary.


Bait the fence before you put your hives in.


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## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

Tenbears, that's a little like saying muzzle energy of a firearm is not important.

Most fence chargers use nearly instantaneous capacitive discharge to deliver a shock every second or two. For such a design, peak voltage and the joule rating is great way to rate the punch they deliver. Implicit in this is a delivery of a brief high current which, if sustained, would be dangerous. Rating such a system in joules is not misleading at all. Since voltage, current, time, and energy are all tied together mathematically, and since the requirement is to apply a voltage for a very short pulse, joules is the logical way to rate them.

Energy storage in a capacitor is (V^2 C)/2, half the voltage squared times the capacitance. I used this to design my capacitive discharge welder, and that's just what they've done for fence chargers ... rate the energy stored in a capacitor used to deliver the jolt.


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## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*



Cloverdale said:


> Bait the fence before you put your hives in.


So when do you place the hives in. And how long do you wait to determine that the bait was taken by a bear and not a crow. And lets suppose the wind, a crow or what ever knocks the bacon off and it lands 2 feet inside the fence, then the bear attempting to get the bacon gets his head well in between the fence wires before getting shocked. The resulting shock sends him forward rather than backward. Now at best you have taught a bear that if he charges the fence he can mow it down, ground it out, and get what he wants. At worst you have a bear inside the fence scared to get out.. Again I ask Why tempt fate?


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## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*



Phoebee said:


> Tenbears, that's a little like saying muzzle energy of a firearm is not important.
> 
> No it is not. Muzzle energy is a absolute calculation which will result in the same results in terms of foot pounds of energy.
> 
> ...


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## Cloverdale (Mar 26, 2012)

*Re: Solar fence sharger for bears*



Tenbears said:


> So when do you place the hives in. And how long do you wait to determine that the bait was taken by a bear and not a crow. And lets suppose the wind, a crow or what ever knocks the bacon off and it lands 2 feet inside the fence, then the bear attempting to get the bacon gets his head well in between the fence wires before getting shocked. The resulting shock sends him forward rather than backward. Now at best you have taught a bear that if he charges the fence he can mow it down, ground it out, and get what he wants. At worst you have a bear inside the fence scared to get out.. Again I ask Why tempt fate?


I have a local beekeeping friend that belongs to the Southern Tier Beekeeping club; they advocate baiting the fence by hanging sardine cans. Me, I figure that the bear would get in if he wants to, so I do a lot of praying...:thumbsup:


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## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

Tenbears, I will not be depositing any money with you because it is patently obvious that your design for an electric fence charger is unworkable. There are all manner of analogous physical phenomena that you would conclude are impossible. Starting a fire by striking a flint, firing a flash to illuminate a photograph, striking a nail with a hammer ... I could go on all day. You'd simply assume the energy is spread out over a month and conclude conclusively that none of these operations will work.

And then you'd recommend a 5A 8000 volt continuous DC power supply as a fence charger. And it would kill everything it touched, because it does not deliver a short burst of energy, but instead continuous power.

I conclude you are too unfamiliar with the "jewel" unit to spell it, much less understand it conceptually.


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## Cloverdale (Mar 26, 2012)

*Re: Solar fence sharger for bears*



Phoebee said:


> Tenbears, I will not be depositing any money with you because it is patently obvious that your design for an electric fence charger is unworkable. There are all manner of analogous physical phenomena that you would conclude are impossible. Starting a fire by striking a flint, firing a flash to illuminate a photograph, striking a nail with a hammer ... I could go on all day. You'd simply assume the energy is spread out over a month and conclude conclusively that none of these operations will work.
> 
> And then you'd recommend a 5A 8000 volt continuous DC power supply as a fence charger. And it would kill everything it touched, because it does not deliver a short burst of energy, but instead continuous power.
> 
> I conclude you are too unfamiliar with the "jewel" unit to spell it, much less understand it conceptually.


Um, now that "we" are nitpicking, he did spell it correctly in the first posts…back to being cordial sounds good to me.


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## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*



Tenbears said:


> let me see if I can help ... .... ...


You have made it clear that you don't believe that a _joule rating_ is of any value in evaluating fence chargers. So what alternative evaluation method do you think is a better judge of fence chargers?


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## longtom (May 8, 2013)

*Re: Solar fence sharger for bears*

So Tenbears, what is your recommendation for a good solar fencer? Is the Parmak 6 good enough?


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## Brad Bee (Apr 15, 2013)

*Re: Solar fence sharger for bears*

I don't know anything about bears, but I've been running electric fence chargers all my life. We have several miles of electric fence....

All I know about joule rating on a fencer is that the higher the joules, the worse it hurts when you touch the fence. A low joule rating makes for a weak fence.


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## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*



Rader Sidetrack said:


> You have made it clear that you don't believe that a _joule rating_ is of any value in evaluating fence chargers. So what alternative evaluation method do you think is a better judge of fence chargers?


Volts and recommended field distance has worked for years.


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## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*



longtom said:


> So Tenbears, what is your recommendation for a good solar fencer? Is the Parmak 6 good enough?


I believe so.


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## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

"Recommended field distance" is not in my list of fundamental units of physics. Were that useful, then the little charger I used to keep flying squirrels from chewing on the cabin would be plenty for the 160 ft of high visibility tape encircling my tiny apiary. 

I think the big one has a "ten mile" rating. But exactly what does that mean? What is the conductivity of the earth against which that standard was applied? With or without grounded fence wires? Against what types of animals?

You've stated, and I concur, that current delivered by the fence is an important factor in the delivery of shock. But just how do you calculate delivered current from "Recommended field distance"?

I'm a guy who has had EMP testing done on military products to the 30 kV per meter level, so I have a pretty good idea of how persnikity standards can get for high voltage pulsed waveforms for passing Mil-STD-xxx. And I'm also a guy who has performed many UL tests on a variety of electrical products, and I know they're persnikity as well. I've got a GR 1863 megger just to my right. I'm fully aware that 50 mA through the body is considered potentially lethal (less for the young and heart patients), that 50 microamps through the heart will induce fibrillation, and that 5 mA is the trip current for a GFCI. Now, you may be right and maybe UL does not recognize joules as a rating for fence chargers. But you're going to have to convince me that they recognize "Recommended field distance".


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## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*



Tenbears said:


> Volts and recommended field distance has worked for years.


Well, lets look at two models both made by Parmac, the Mark 8 at 30 miles, and the Magnum SolarPak 12, also at 30 miles according to the charts below. Both also have the same 13,500 voltage (open circuit). Based on _your _criteria, these two would both have the same critter stopping power.

And yet you can see that the manufacturer assigns _different _joule ratings, at 4.9 and 3.1 joules respectively. What would cause the manufacturer to rate them differently? Do you really believe there is no difference?


> ImageProduct NameModelWarrantyInstallationRangeJoules LowJoules HighPower SourceFence Voltage - Open CircuitFence Voltage - 500 ohmFence Voltage - 100 ohmFence Volatge - 50 ohmDisplayRange MasterRM-12 YearsIndoor only100 miles1.86.6+110v-120v AC16,0009,7507,5004,600DigitalSuper Energizer 5SE-51 YearIndoor only50 miles1.56.3+110v-120v AC14,5008,7506,3004,300DigitalMark 8M81 YearIndoor only30 miles1.14.9+110v-120v AC13,5007,7504,600N/ADigitalField Master 3FM-31 YearIndoor only15 miles0.992.5+110v-120v AC10,0006,7003,500N/AOperational LightHorse SurroundHS-1001 YearIndoor only5 miles0.652.0+110v-120v AC9,5002,450N/AN/AOperational LightPet-GardPG-501 YearIndoor only2 milesN/AN/A110v-120v ACN/AN/AN/AN/AN/A
> 
> 
> 
> ...


(Note depending on the width of your display, parts of the chart may not be visible initially. But at the bottom of each chart is a horizontal slider bar that you can use to move around each chart window.)


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## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*



Phoebee said:


> Tenbears, I will not be depositing any money with you because it is patently obvious that your design for an electric fence charger is unworkable. There are all manner of analogous physical phenomena that you would conclude are impossible. Starting a fire by striking a flint, firing a flash to illuminate a photograph, striking a nail with a hammer ... I could go on all day. You'd simply assume the energy is spread out over a month and conclude conclusively that none of these operations will work.I conclude you are too unfamiliar with the "jewel" unit to spell it, much less understand it conceptually.


 I understand the concept of joules perfectly. It is the formula that does not work. By the way I used Joules 5 times in that post and mistyped once. So that means what? Let he among you cast the first stone. and just what is Patently? Or do you not know how to spell Blatantly? See with all your self professed education you still are infallible, as are all Men. There is nothing wrong with it. What is wrong is being so stead fast on being correct that even when faced with Blatant evidence that mathematically the joule formula is flawed. One would resort to Pointing out such a trivial misnomer. By your own admission you see that a low voltage low amperage with a long on time will not work in spite of the fact according to the mathematics of the joule rating it would be better. I fully understand the backlash effect of rapid discharge electricity and its ability to deliver a shock. But a flawed system is a flawed system regardless.


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## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

Rader, something on the Magnum Solar-Pak 12 caught my eye. They state on one bullet line of the link:

Charges up to 30 miles of fence - 3 joules*

I can't see what the * refers to. I notice they have two energy levels. I'm looking at that little PV panel and guessing it puts out maybe 10-12 W at full sun, and I think that unit would need 40 W in full sun to reliably run in our area. Evidently the 3 joules is conditional. Do you know the limits?

Looks like a nice charger, but those of us in cloudy areas might need 3x the panel area.


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## Phoebee (Jan 29, 2014)

Tenbears, I patently meant patently. Try looking it up with a Thesarus.

Enough of this. The question is, what makes a bear dump its load and leave the hives alone.

The answer is, a walloping brute of a fence charger, not some dinky little one. Maybe just look for a picture of a bear on the box.

Actually, you and I agree on one thing ... maybe it is not a great idea to deliberately ATTRACT the bears. Rather, make sure that if they hit the fence, they don't want to do it twice. My apiary is in the front yard, and I'd rather minimize the bruin traffic.


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## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*

_Phoebee_, I think you are overestimating the solar panel wattage required to keep the battery charged. Parmak says


> The Mark 8 operates for less than 7 cents a *month* at 7 cents per kwh.
> http://www.baygard.com/product_details.php?PId=7


so it consumes about 1 KWH per month, or 33 watthours each 24 hour day. Other models may more or less, but I think a 40 watt solar panel is significant overkill.


As far as the asterisk goes, earlier I looked at the original page for an explanation, and could not find one.


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## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

Rader, I was basing my estimate on 3 joules at a 1.4 second pulse rate, or about 2 watts of power to run it. The PV panel will get full power for about 4 hours on a sunny day, and may make next to nothing if cloudy. That's 160 watt hours one day that has to last for several more. I think our numbers are close, I just have less faith in sunshine.

Just paranoid, I guess. My first two Southern States solar fence chargers some years back kept going dead.


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## laketrout (Mar 5, 2013)

*Re: Solar fence sharger for bears*

I might be having a issue with trees in the area of my parmack 12 shadowing the solar panel at certain times of the day, other than cutting trees down would a bigger solar panel help and if so would it then over charge the battery .


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## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*

Raider. Yes they are the same. providing the amperage is the same. Then the difference is in the on time. But since we don't have the amperage we cannot determine that. since Joules is a calculation of volts, amps, and on time.


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## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*

I have looked at lots of fence charger spec pages, but I can't recall _any _specifying amps. That really points out the problem. Since amps is rarely specified/available, joules has become a de facto stand-in.

Joules may not be a perfect rating system, but unless you have amp ratings available somewhere, I don't see any real alternatives.


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## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*



laketrout said:


> I might be having a issue with trees in the area of my parmack 12 shadowing the solar panel at certain times of the day, other than cutting trees down would a bigger solar panel help and if so would it then over charge the battery .


It depends on how well-designed the solar charging system is. My old Southern States units had no 12 V charge regulation system at all. I tried adding enough panel to keep the battery charged and the little gel cell dried out. I tried adding a 12 V RV battery and the fence charger burned out.

If the system has an actual solar battery charge regulation circuit it might work pretty well, but you'd need to be sure the charger can take the added panel. 

Other solution: move the fence charger to a sunny location. They make underground cable for fence chargers to get it over to where you need it.

Or use an independent 12 V solar battery system to run a 12 V fence charger.


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## Allen Martens (Jan 13, 2007)

*Re: Solar fence sharger for bears*

Parmack 12 is an excellent fencer for a bear fence. Parmack 6 are undersized and are more likely to fail to keep a bear out.

A 5 watt solar panel is adequate for keeping the battery charged unless vegetation is touching the fence. I have found that not all 5 watt rated panels are equal. Some may supply half the amps they should. My experience is that with the Solar Parmark I had had the least difficulties -- an excellent unit.

As far as baiting goes - not sure which would attract a bear from a greater distance - bait or the strong smell of brood pheromone in the evening. I don't use bait unless I am setting up a fence around a beeyard that was not fenced and was hit by a bear. In summer we keep most of our bees in temporary yards on field where bears rarely visit (once every 5 - 10 years). If a bear comes around and hits a bee yard we put up a fence and tie some bacon to the wires. Never had a bear strike again in this situation.


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## laketrout (Mar 5, 2013)

*Re: Solar fence sharger for bears*

Could the panel it self be moved to a sunny area , it would be easier to just move the panel itself to a pole about 15 ft. away .


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## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*

Typically solar fence chargers have the solar panel itself integrated into the control box housing. If you have one of those you can't separately place the box away from the panel without having weather-tightness problems with the box.

If you want to do that, one option is buy a 12 volt battery type fence charger, and a separate battery and separate solar panel. It will likely cost more than an integrated system, but may be easier to fix when it has problems.


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## Allen Martens (Jan 13, 2007)

*Re: Solar fence sharger for bears*

I have both integrated units and units with separate parts. The fence chargers are parmaks in both cases but for the unit with separate parts I don't have parmak panels.

For the separate unit I do move the solar panel away from the charger at times to a more sunny locations.

Typically the integrated units cost me more but are much more convenient and are worth the extra money IMO.


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## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*



Rader Sidetrack said:


> I have looked at lots of fence charger spec pages, but I can't recall _any _specifying amps. That really points out the problem. Since amps is rarely specified/available, joules has become a de facto stand-in.
> 
> Joules may not be a perfect rating system, but unless you have amp ratings available somewhere, I don't see any real alternatives.


 Now You are beginning to grasp my feelings on joules. Amperes are required to maintain voltage downrange, however amperage is also what makes electricity deadly. in you earlier comparison the different in joules was most likely a result of increased amperes , however in the equation to determine joules one can accomplish the same results by increasing other factors such as on time. and that is where I have the problem. every day more Chinese companies are shipping more products to the us. As they have done with honey the Chinese government subsidies the manufactures of these products to make the sale price cheaper for the consumer. These companies realize that they can manufacture low voltage low amperage chargers with long pulse rates giving them much higher joule ratings. By leaving the pulse on longer it increases the down range voltage closer to the max giving the charger a higher joule rating.

We Have people bring these chargers into the store for repair regularly, because they have a 3 Joule charger that will not keep their cow in the pasture. or their dog out. 
" Sir, this charger does not have ample Power to charge your 2 acres barnyard."
"Bull, it 3 joules! My buddy says 3 joules will keep Godzilla in! 

Now we are the jerks for not being able to fix something that is not broken, just poorly rated.


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## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*



Tenbears said:


> Amperes are required to maintain voltage downrange, however amperage is also what makes electricity deadly.


I do not agree that amps (current flow) is required to maintain voltage downrange. When you have weeds touching the line, there will be current (amps) through the weeds, and voltage on the fence line will drop as a result. The highest voltage is present in a fence line with no weeds touching and no material current flow. (Of course, it is the _current _flow thru the critter touching the line that provides the "shock" value.)


I submit that the most likely cause of a fence charger (that isn't dysfunctional) not being able to keep cows on the correct side of the fence is poor ground issues in the installation - i.e. "operator error".


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## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

Here's the problem, no one number can do the whole job.

You need voltage. Rader's chart shows that the larger chargers, particularly the ones being recommended here, put out voltage above 7 kV. That's necessary to jump from the fence wire across a heavy layer of coarse fur and into an animal noted to be thick-skinned. Bears and cattle qualify. Bears have more fur but don't have hooves. Either act as insulators and only voltage gets around that problem.

Amperage: Yes, that's what hurts but you can't specify amperage without the time it is applied. If you put an 8 kV power supply capable of, say, 0.10 A (100 milliamps) continuous output, it will kill a human easily. But if you limit the supply to a non-lethal current that is within the shock limits considered absolutely safe for humans (let's use 5 mA) the fence will tingle a little but won't hurt enough.

Let's say the supply can put out 8 kV and unlimited current. My skin resistance is usually around 100,000 ohms, maybe less if I'm sweaty. If my footwear is dry, I may even not conduct to ground at all without a high voltage arc. But if an arc forms, and I'm barefoot on highly conductive soil, say I'm a 100k resistor across 8 kV and ground. Ohms law: I'll conduct 80 mA. It does not matter if the power supply can source 100 amps, that's about what I'll conduct due to the voltage and my resistance. So even the amps rating is a bit of a fantasy, as long as it can source everything the body can conduct.

But again, 80 mA will likely kill me. So how to prevent that? The answer is to make the voltage and current a brief pulse. That's what virtually all agricultural fence chargers do. They can put out voltage with enough current behind it to really, really hurt, but for such a brief time that it isn't lethal. And because of the sharp increase in voltage at the pulse onset, we have a dV/dt term and the shock will be felt due to capacitance even if the victim has hooves or rubber shoes. However, if the pulse is TOO short, the whole system has Maxwell's equations to deal with and the pulse will be limited by them, and may deliver too little energy to even be felt. In other words, in spite of Tenbears objecting to that time parameter (which definitely is there), you can't just specify amps, either. *If time is not part of the design, the thing is unworkable.*

What about joules? If the duration of the pulse is a vital part of the whole scheme, we're back to joules. Well, yeah, if you mush a joule over too long a period, the jolt is similarly mushed down to a joke. But that's poor engineering. Are there poorly engineered fence chargers out there? I trashed two some years ago that certainly were. So I'm sure there are a few Chinese engineers who can't figure out how to make a 3 joule capacitive discharge go fast enough to zap a bear. But don't blame the unit of energy storage. The real fruit of this discussion is not if we should replace one meaningful engineering unit with a vague "miles of fence" rating.

*The real purpose of this thread is to find which chargers actually work.* There are some answers in this forum. They have less to do with numbers than with experience. 

The numbers do matter: a charger needs sufficient voltage and, if pulsed, sufficient energy storage. If these are present and the engineer was competent, the bear gets a strong negative reinforcement. If incompetently engineered, poorly grounded, in dry nonconductive soil, poorly installed, or the battery went dead, the bear gets baby bees for dinner, regardless of the numbers.

For that matter, if the bear manages to hit the electric fence at a dead run, odds are he'll avoid the shock, or tear the fence down on sheer momentum. Ever see a black bear suddenly startled? I think they must go 0-40 in about one second. Generally uphill. They don't turn, they just barrel thru anything in their way.

Which is why Fort Bee features a strong mechanical fence behind the electric fence.

I realize a bear fence is a lot of bother, and commercial beekeepers can't have fences around every place they move their hives, but if you keep your bees in one place and this added measure is feasible for you, give it some consideration.


----------



## laketrout (Mar 5, 2013)

*Re: Solar fence sharger for bears*

On the parmack 12 the solar panel is just riveted to the top of the housing , I already pivoted 90 degrees to catch the southern sky , it would be easy to remove and splice in more wire to mount it remotely as long as the longer wire won't hurt anything and I can get the same wire .


----------



## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

Low voltage wiring suffers badly from added resistance if you try to splice in an extension. If you are stretching more than a couple of feet, rather than using the same wire, go a size or two larger. Otherwise you'll get a voltage drop and your battery won't charge as well.

Use a grade of wire rated for sun and weather exposure.

I still wish someone would try out high voltage underground wire for feeding fences. I just discovered that a couple of weeks ago in the instructions for my new charger. It might help me feed from the apiary to the garden fence, and save me from buying a second expensive charger. So try that and tell me if it works!


----------



## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*

My neighbor uses regular UF wire (household direct burial wire) buried to bridge around his gate openings. Yes its only rated at 600 volts, but it seems to work for him - I have inadvertently gotten a good zap from his fences, so regardless of the rating, UF works in some situations.


----------



## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

(Deleted double post)


----------



## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*



Rader Sidetrack said:


> My neighbor uses regular UF wire (household direct burial wire) buried to bridge around his gate openings. Yes its only rated at 600 volts, but it seems to work for him - I have inadvertently gotten a good zap from his fences, so regardless of the rating, UF works in some situations.


The better grades of coaxial cable can handle high voltage, too. I've bought high voltage supplies that came with coax on the output lines, generally the grades with high density polyethylene inner insulators. But don't tell the fence charger company. They may void your warranty if you don't buy their underground cable.

UF could be a good choice for running solar over to the charger. Pick a couple of gages heavier than the original wire, and make sure the UF has a sunlight resistance rating (they generally seem to so they can be exposed at either end of their underground runs.

Power companies run direct burial cable rated for as much as 30 kV. Call Miss Utility before you dig, PLEASE!!!


----------



## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*



Phoebee said:


> In other words, in spite of Tenbears objecting to that time parameter (which definitely is there), you can't just specify amps, either. *If time is not part of the design, the thing is unworkable.*
> 
> What about joules? If the duration of the pulse is a vital part of the whole scheme, we're back to joules. Well, yeah, if you mush a joule over too long a period, the jolt is similarly mushed down to a joke. But that's poor engineering. Are there poorly engineered fence chargers out there? I trashed two some years ago that certainly were. So I'm sure there are a few Chinese engineers who can't figure out how to make a 3 joule capacitive discharge go fast enough to zap a bear. But don't blame the unit of energy storage. The real fruit of this discussion is not if we should replace one meaningful engineering unit with a vague "miles of fence" rating.
> 
> ...


 My Objection has never been with the time factor in determining Joules, Nor with most of what you have stated in regards to fencers, My problem is was and forever will be with using joules as a method on rating a fencers performance. 

The more you speak the more confused I become. you obviously have enough knowledge to understand the logistic of electronics, however you defend a poor system of measurements. Joules are fine if you want to raise apples, and they have their place in the mathematics of electronics. however It is my opinion that they fall short as a measure for fencers. 


watts x time =Joules. for those who do not know amps X volts =watts.

Can we not agree that 10,000 volts @ 5 amps =50,000 watts,, X 1/10,000 of a second =5 joules. and that would be sufficient power to detour most animals at the source and a good way down the fence.

now take 5000 V @.1A =500W X 1/100 of a second = 5 joules. both you and I Know that is not a quality fence charger for much more than small pets and we both know why. 

So please, I do fully understand capacitor rebound, and shaping the current, and I do know that the discharge of a cap is not a sustainable long tern current supply

However, to mark that charger as a 5 joule charger would in no way be deceptive. It would be factual. That is where I have a problem with the rating For a rating to have merit it must not be able to be manipulated, The product must indicate a value that is consistent.


----------



## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*

> For a rating to have merit it must not be able to be manipulated, The product must indicate a value that is consistent.

But your 'alternative' to rating by joules is 'recommended field distance' ...


Tenbears said:


> Volts and recommended field distance has worked for years.


It certainly seems that 'recommended field distance' is easily manipulated.


----------



## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

Tenbears, you actually just answered your own question, managed to agree with me, and yet at the very same time mocked yourself.

Do you honestly still believe your original and repeated assertion that some vague and undefined "miles of fence" rating has any meaning whatsoever? At least joules, combined with a couple of other terms, would have some measurable meaning.

YES, a full description of the way the shock is delivered is the best way to show how much zap the fence charger can deliver. And it is pretty similar to the standards for defining an EMP test pulse. 

I will quibble about the 10 kV @ 5A bit ... I doubt even considering capacitance of the victim that you'd get quite that much to flow through most organisms. I doubt it could actually be delivered. 0.1 A would be quite enough, though the 10 kV would be better than 5 kV for bears.


----------



## RudyT (Jan 25, 2012)

*Re: Solar fence sharger for bears*

In spite of the ongoing argument about measurement, I just ordered 2 Permak Magnum 12V solar fencing units. If someone wants to nominate a better solar fencing unit, I'd be interested to know. So once again Beesource was helpful as well as entertaining.


----------



## laketrout (Mar 5, 2013)

*Re: Solar fence sharger for bears*

Rudy I don't think you will be sorry , there good units , just make sure its facing the right way !!!


----------



## Duncan151 (Aug 3, 2013)

*Re: Solar fence sharger for bears*



laketrout said:


> Rudy I don't think you will be sorry , there good units , just make sure its facing the right way !!!


What do you mean by right way? My Paramark says, "this way towards enemy".


----------



## Santa Caras (Aug 14, 2013)

*Re: Solar fence sharger for bears*

Gosh, I'm just really glad I dont have bears in my area (knock on wood)
My wife would kill me if I wanted to buy more equipment for the bees!!!
She's not really into "jewels" but does like a nice fur coat so maybe I can talk her into a new rifle instead!
Everyones happy then! (cept the bear!)


----------



## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

The thing that concerns me right now is, exactly what happens when a skunk hits that bottom line of fence tape, the one about skunk-high off the ground? In the front yard. Three joules, 7.5 kV, causing a sudden clenching of muscles ....


----------



## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*



Phoebee said:


> Tenbears, you actually just answered your own question, managed to agree with me, and yet at the very same time mocked yourself.



I mock Myself!?



Phoebee said:


> There are all manner of analogous physical phenomena that you would conclude are impossible. Starting a fire by striking a flint, firing a flash to illuminate a photograph, striking a nail with a hammer ... I could go on all day. You'd simply assume the energy is spread out over a month and conclude conclusively that none of these operations will work.





Phoebee said:


> I conclude you are too unfamiliar with the "jewel" unit to spell it, much less understand it conceptually


 That is 3 times you have insulted me. it WILL NOT happen many more!

If you cannot take part in a discussion without using insulting statements then I strongly suggest you keep your impressions to yourself as far as I am concerned. 

NOW. since you want to turn this discussion into something else. Think about this. Someone wrote it is not so much about numbers as it is about experience. wonder who it was? And there are a few points I would like to clear up on that matter.
You live in Manassas Virginia. How much real world experience do you have with bear bothering your bee hives? Now before you answer know that I have had a discussion with conservation officer Ace from the Virginia department of fish and game who tells me that there is a small bear population in the western portion of Prince William County the county in which Manassas is located. and that NO bear were harvested in Prince William County in the 2013 season which runs from October 5 through January 4thSome 3 months! And there are NO bear in Fairfax County immediately to it's north. Although I believe there is a pile of bear scat there I do not believe it is at this ladies bee yard!

On the other hand I live in Clarian county, which is generally in the top ten counties of Pa. for bear harvest. Last season 77 bear were harvest in the 3 days of archery and the 4 days of firearm seasons combined. All adjoining counties also had substantial bear harvests. Over the 2013/2014 winter I have seen over 30 bear within 200 yards of my home bee yard.

So where is your real world bear experience coming from. While your sitting behind your desk pitching ideas to some bureaucrat, like some kind of used car salesman? Stick with the skunks in your front yard and leave the bears to us MEN who live in the wilds.

Please tell me I am wrong according to the formula for determining Joules .1volt @ .1 A with a continuous on time has UNLINITED joules!


----------



## Michael Bush (Aug 2, 2002)

*Re: Solar fence sharger for bears*

That is the problem with numerics. It only measure some carefully defined thing and the parameters are often different than the thing we think we are measuring. Weight is one of those. How difficult something is to lift is only loosely related to weight, but we tend to think it is a direct relationship. According the physicists the recoil of a 30 pound rifle firing a 50 BMG cartridge is exactly the same as the recoil of a 10 pound rifle firing the same round. Technically this is true. But we tend to use the term "recoil" in a "non physicist" context. What most of us mean is how painful it is to shoot... and that is dramatically different. It is actually almost the opposite issue with Joules. Time makes a lot of difference because it is included in Joules and not in recoil... Reality is often more complex than simple numerics indicate.


----------



## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

Tenbears, our apiary is in West Virginia. The exact site was bisected by a small black bear raiding a birdfeeder a few years back, the origin of my observation about their acceleration. I will note that Pennsylvania is noted for having particularly large black bears, not uncommonly topping their WV cousins by a good 200 pounds.

You fail to justify your assertions about fence length ratings. Show me the math on that.

As for placing insults, that's pretty much all you've done since I mentioned joule ratings. And that mention was based on earlier recommendations by others in this forum, and their experience. And I was recommending the experience of people in this forum who had direct experience with certain chargers. Whom you've also insulted.

Michael, I've never fired a .50 BMG rifle, 'tho I did get to handle a Barrett once. I've been told, and can only take it on what I've been told, that the Barrett has a muzzle blast deflector that relieves much of the recoil. I've got a couple of dummy BMG rounds and placing them side to side with a .30-06 that gives me a fair smack, it is difficult to believe those things don't kill at both ends. I already nearly faint when I see the price per round of the 30-cal ammo ... I'm too cheap to buy anything that costs over $5 a round to attempt the experiment. And I'm too chicken.


----------



## Michael Bush (Aug 2, 2002)

*Re: Solar fence sharger for bears*

If it puts it in the realm of reality, try a 4 1/2 pound .30-06 and a 12 pounds .30-06 with no muzzle brakes involved... they have the same recoil, but the 4 1/2 pounder hurts more...


----------



## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*



Michael Bush said:


> If it puts it in the realm of reality, try a 4 1/2 pound .30-06 and a 12 pounds .30-06 with no muzzle brakes involved... they have the same recoil, but the 4 1/2 pounder hurts more...


All I've got is my "assault rifle". Well, the WWI version ... Remington Model of 1917. That should be around 10 lbs. I have not tried it out since I bought a shoulder cushion for it ... can make one a tad sore after a few rounds. I've also got a box of 160 grain to try as an alternative to the 180 grain bullets I've fired up to now. Bullet weight affects recoil, but from what I've read the results can be counterintuitive, as muzzle velocity affects the recoil profoundly, and the lighter bullet should reach higher velocity.

I wouldn't mind trying out a Model 700, but they're typically only a couple of pounds lighter than the P17.


----------



## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*

phoebee, Please quote any insult I made to you or anyone. I had the foresight to post those you directed at me. Please do the same. 

And answer the simple yes or no question I have asked. 
"Please tell me I am wrong according to the formula for determining Joules .1volt @ .1 A with a continuous on time has UNLINITED joules!" 

don't mince words or divert the subject just do the math and answer the question!


----------



## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

Sorry. Did I misinterpret this? I thought it must be an insult:

"So where is your real world bear experience coming from. While your sitting behind your desk pitching ideas to some bureaucrat, like some kind of used car salesman? Stick with the skunks in your front yard and leave the bears to us MEN who live in the wilds."

I fully stated, in a long post above, just what my understanding of the process of making a good shock comes from, and from a math standpoint we're in good agreement on the meaning of joules. I also agreed with you that baiting (and I was hoping we meant bears) was probably a bad idea. That we both understand joules should be obvious enough from my posts above and discussion of this should end.

Where we differ on joules is that I think they're a reasonable measure of stored energy which, if properly applied, can indicate that an effective shock may be delivered, whereas you are fixated on the possibility that an incompentent designer could make an ineffective charger. Which I have acknowledged. I think you're thus also insulting compentent designers.

What has not been clarified is your claims regarding appropriate ratings for fence chargers, which you have stated a couple of times in terms such as this one from page 2: "Volts and recommended field distance has worked for years."

And I'd like to know how "recommended field distance" is calculated, and how it relates to deterring bears. You're repeatedly skirted this, preferring instead to insult anyone who asks.


----------



## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*

O I see, you have made numerous affronts on me and after all is said and done I dish some back you use that to substantiate your claim. However you said "Insults are all pretty much I have done since you mentioned Joules." And That is a boldfaced lie! but that is irreverent at this stage.

Just answer the simple YES or NO question You seem to be doing everything in your power to avoid 
"Please tell me I am wrong according to the formula for determining Joules .1volt @ .1 A with a continuous on time has UNLINITED joules!" 
Please I beseech you tell Me!


----------



## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*



Tenbears said:


> "Please tell me I am wrong according to the formula for determining Joules .1volt @ .1 A with a continuous on time has UNLINITED joules!"


What kind of electric fence charger has a voltage of 0.1 volts? :s


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## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

Rader, it may be informative to check out this page and see if you recognize some language.

https://www.afence.com/Electric_Fence/how_to_elecfence/Joulerelation.htm

Tenbears, we're done here. You refuse to answer the question posed. 

Your first post in this thread included a comment about the spelling originally on the thread title ("sharger"), then reacted with rage when I pointed out your mis-spelling. So if I may point out, you're having some trouble taking a little ribbing. 

Are you, by any chance, connected with American Fence and Supply Company?


----------



## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*

I believe I had posted this before. The main difference is one can readily test the stated voltage, and one can easily hook that fencer to a fence of the recommended field distance and test the extremes to determine if they fall true. Truth in advertising laws can be used to confront the manufacturer and require conformation. Are they perfect? No! I never said they were, in fact I have recommended always using a fencer that is rated double the intended fence. But they have served the agriculture industry for decades. and until something better comes along will have to do. they need not be replaced by a more severel flawed measurement system.
that can and is manipulated by innocuous numbers that can be manipulated to fulfill the rating and never come close to the actual Shockability.


----------



## Brad Bee (Apr 15, 2013)

*Re: Solar fence sharger for bears*


----------



## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*

Maybe instead we need a cartoon of someone repeatedly _shocking _that dead horse with an *electric *'_*cattle prod'*_ ! 

:lpf:


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## Brad Bee (Apr 15, 2013)

*Re: Solar fence sharger for bears*



Rader Sidetrack said:


> Maybe instead we need a cartoon of someone repeatedly _shocking _that dead horse with an *electric *'_*cattle prod'*_ !
> 
> :lpf:


How many joules?


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## VickyLynn (Jun 20, 2011)

*Re: Solar fence sharger for bears*

Hi voltage is what is needed - the zap has to hurt. Baiting is needed (I use peanut butter in a foil pocket, wrapped around electric netting) so the bear tastes or sniffs with sensitive parts. If possible, set up the fence before you put in your hives, so wildlife is dissuaded from visiting before there is anything there to damage.

Use a New Zealand style charger with high voltage, short time zap. The American lower voltage, but longer time zap will not work. Check out 
Wellscroft Fence Systems. They are very knowlegable and helpful.

http://www.wellscroft.com/catalog/index.html#/26/


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## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*

Uh Oh! 

All the Speedcraft chargers I saw at the Wellscroft link in post #73 seem to be rated in '_joules_'.  No mention of 'recommended field distance'.


The largest one, Spreedrite 18000i, is rated at 18 joules!


----------



## Duncan151 (Aug 3, 2013)

*Re: Solar fence sharger for bears*



The largest one said:


> Sounds like a lawsuit waiting to happen there!


----------



## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

The poor chipmunks! They'll be vaporized!

Actually, I'm kinda worried about ME!


----------



## I'llbeedan (Mar 31, 2013)

*Re: Solar fence sharger for bears*

This is quite an interesting thread. and the material on both sides seems based on facts. no I do not know a lot about electrical tings. I am but a lowly machinist.
here is how I see it.

Phoebee Sounds very knowledgeable about electronics and his credentials in the area are impressive, However , he also seems insulting and pompous at times. I can see where someone would be insulted. and so do other as cloverdale quoted Phoebee and said can we go back to being civil. 

Now I have met Tenbears. I have been to his shop, and to his farm. So maybe this colors my opinions. But I can tell you he is a kind giving person who helps out anyone, and I can tell you he also has some electrical knowledge. I had 3 moultree trail cameras all quit working after a year he took them and fixed them they have worked for three years and still do, BTW he charged $3.45 each to fix. 
I find it interesting in post 32 Phoebee wrote enough of this. tenbears from then on discussed this tread with others but did not respond to any of yours. Then in post #45 Phobee brought him back into it with. "In other words, in spite of Tenbears objecting to that time parameter (which definitely is there),"
Even after that tenbears responce seemed to be non confrontational. Untill Phoebee insulted tenbears again, Raider sidetrack, and Phoebee seem to be a good team though! Raider sets tenbears up so Phoebee can try to knock him down. 


Now it is great that you so throngly stick to your guns! but how you do it does you no credit! I if you knew tenbears I would be willing to bet you would not speek to him in the manner you have here more than once.
There are all manner of analogous physical phenomena that you would conclude are impossible. Starting a fire by striking a flint, firing a flash to illuminate a photograph, striking a nail with a hammer ... I could go on all day. You'd simply assume the energy is spread out over a month and conclude conclusively that none of these operations will work.I conclude you are too unfamiliar with the "jewel" unit to spell it, much less understand it conceptually.

I would read this as a fancy way of saying . You are so stupit that you cannot understand the simplest of mechanical reactions so much so I coulds discuss the simple things you do not understand for an entire day. And I think that since your spelling is incorrect you are a total moron.


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## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*

My opinion is that a _joule rating_ for a fence charger may be imperfect, but there are no better ratings available across different chargers manufacturers. Certainly '_recommended field distance_' is not a better measurement. What are the criteria? Are they published anywhere? Anyone have any links?

Much of _Tenbears _objections (posted earlier in this thread) with the 'joule' rating is taken directly from the Parmak/Bayguard FAQ page here:
http://www.baygard.com/faq_details.php?FId=1
Other parts of his comments were taken from the American Fence website as _Phoebee _earlier pointed out. I haven't verified this, but my _guess _is that American Fence is a Parmak dealer.
Note that _Tenbears _did not credit any charger manufacturer as being the source of his comments.

Selling fence chargers is a very competitive market. Its not surprising that some manufacturers don't agree on what is the best rating system. But in spite of Parmak's objections to using joules as a rating system, the joule rating of each of _*their *_chargers is featured _prominently _in their marketing material.

Other charger manufacturers publish _joule _ratings as well. Imperfect as a joule rating system may be, there isn't a better rating system that is anywhere _close _to being a standard.


----------



## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

I wish to very gently point out that a recommendation Tenbears has for using the "recommended field distance" or "miles of fence" rating, while it might be useful for farmers with large fields to protect, would be highly misleading for small apiaries. He quite reasonably recommends getting a charger that rated for several times your total fence length. But an apiary might have a 200 ft perimeter (mine is a lot smaller than that). Even allowing for 5 runs of wire around it, that's under 1/5 of a mile. A one mile fence charger against bears is not going to have much effect. And I think Tenbears would say so.

The same would apply to joules. Not all manufacturers calculate it the same (is it internal storage, or delivered joules?), and TenBears is correct that the time over which the jolt is delivered from the charged capacitor storing the joules can vary. If any are so dimwitted or dishonest to be delivering pulses of .1 V at .1 A for 300 second pulse they'd not be in business long. But the same argument can be applied for any reasonably designed charger ... get a bigger one. And look for the peak voltage. But one thing you can say for certain ... don't get one below the 2 J recommendation because you can be *SURE* it won't be enough. That's a vital factor in the less expensive solar chargers.

One thing I'm sure we don't want is a Federal Department of Fence Charger Standards. Comparing notes on these should be a constructive way to figure out what works. Frankly, I'm kinda wishing I got a solar Parmak 12 instead of what I bought.

We have a professional beekeeper (keeps bees for the government) in the club. I need to find out what charger she is using that caused the bears to leave bear droppings. Now _*THATS*_ a rating that you could take to the bank.


----------



## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

Oh, dear, things are worse than I thought. The feds _*are*_ involved. At least in the document linked below.

I was checking to see if there is an ASTM standard for fence chargers (energizers). Not yet. There are standards for fence posts, fittings, wire, grates, etc. An ASTM standard is the proper way to standardize ratings, though it can take some time before a committee can come up with something effective. Some testing I did once caused a major revision of wildland firefighting boots, when the original standard was improperly worded to prevent burns.

But I found this. You'll note it specifies voltage, amps, pulse duration, and joules. It relates joules to fence length. The recommendations they give say the fence length ratings on most chargers are likely grossly exaggerated. They recommend one joule per mile. At that level a Parmak 12 would be a 3.1 mile charger, not 30 miles. A lot depends on the intended use and the environment. This could be a spec for an area with soil that does not conduct well.

http://efotg.sc.egov.usda.gov/references/public/WI/WCS-010.pdf

5. ADDITIONAL SPECIFICATIONS FOR HTPEWF

A. Energizers.
(1) Power Source.
Electronic energizers or power fence controllers shall be installed according to the manufacturer’s recommendations and will meet the following minimum specifications: USDA-NRCS-Wisconsin 10-8
Section IV, Technical Guide
11/09
• High power, low impedance system with solid state circuitry capable of at least 5,000 volt peak output and a short pulse that is less than 300 mAmps in intensity, finished within .0003 of a second and a rate of 35-65 pulses per minute.
• High impact weather resistant cases.
• 110 volt, 220 volt conventional powered electric fence energizers.
• 12-volt battery powered capable of operating three weeks without recharging. If the length of fence requires an energizer of more than 4 joules, a solar charger will be needed on the battery systems.
• Minimum voltage output by livestock species:
- cattle: 3000v
- sheep and goats: 4000v
- hogs and horses: 2000v
• Utilize a safety pace fuse to prevent over pulsing.

(2) Size.
Under normal operating conditions, the energizer should be capable, at a minimum, of producing 1 joule of energy for each mile of wire used. (Joules are units of electrical energy. One joule does about 0.74 ft-lb. of work. Watts x seconds = joules.) If a significant portion of the fence will be exposed to dense vegetation, additional energy requirements may be needed.


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## Allen Martens (Jan 13, 2007)

*Re: Solar fence sharger for bears*



Phoebee said:


> If a significant portion of the fence will be exposed to dense vegetation, additional energy requirements may be needed.


From someone who has about 20 Parmak 12's and likes how they perform, let me rephrase your quote:



Phoebee said:


> If a portion of the fence will be exposed to vegetation, you will get bear damage.


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## camero7 (Sep 21, 2009)

*Re: Solar fence sharger for bears*



> If a portion of the fence will be exposed to vegetation, you will get bear damage.


Agree, just happened.


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## Phoebee (Jan 29, 2014)

*Re: Solar fence sharger for bears*

Somewhere there must be a mother document USDA uses for these state standards. They're pretty consistently using a joule per mile, which sounds a bit simplistic to me. But they are consistently using the same pulse duration (0.0003 sec), and pulse rate. If this does indeed form a standard for low-impedance fence energizers (as they imply), and delivered joules are used, then the relationship between volts, amps, and joules should be valid. If joules stored in a primary capacitor are used, expect something like 30% losses and size up accordingly.

I think the practical experience here may say some number of miles per delivered joule or one weed, whichever the fence wire encounters first. But still one needs voltage and either energy or current necessary specifically for bears. No doubt higher than for a horse fence. I've seen mention of fences for predators, but no specific numbers by species. 

http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_005650.pdf

This one is even more simple-minded. The only mention of voltage is "at least 3000 V". 

http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_018812.pdf


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## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*

Raider, Know your facts jack, Better ask baygard where it came from, I until a minute ago had never been to their site! That quote came from my wordpad file and is from a discussion I had back in the 90s on all outdoors chat when Chinese fencers became so prevalent in our area. I have checked my files and have no contract with Beesourse, or any other forum for exclusivity. 

As is so often the case when a lack of reasonable facts to defend ones position, it is best to resort to an attempt to discredit ones opponent, Political campaign rule#1

YFJW


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## Rader Sidetrack (Nov 30, 2011)

*Re: Solar fence sharger for bears*

> Raider, Know your facts jack, ....

My 'facts' were/are correct. You posted a technical explanation of your objections to using joules as a standard for fence charger evaluation, and your comments match up _word-for-word_ with with a fence charger manufacturer's remarks on that subject.

Regardless of _who _wrote those words originally, or when, Parker-McCrory Mfg (Parmak)/Bayguard and American Fence are using them in an attempt to differentiate their charger products from their competitors' products. 

Readers/members may evaluate cut-n-paste comments from a charger manufacturer differently if they are aware that those same words are indeed from a specific vendor's site.


Even though Parmak and American Fence use those words to disparage _joules _as a charger evaluation standard, they continue to prominently feature the joule ratings of their _own_ products. It is clear that while a joule rating system may be imperfect, there is no _better _charger rating system used across the charger industry.


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## Tenbears (May 15, 2012)

*Re: Solar fence sharger for bears*



Michael Bush said:


> If it puts it in the realm of reality, try a 4 1/2 pound .30-06 and a 12 pounds .30-06 with no muzzle brakes involved... they have the same recoil, but the 4 1/2 pounder hurts more...


In reality although the above references do generate the same recoil. The (felt recoil) the recoil transmitted to the shooter is different. 

Recoil is an expression of newton's third law for every action there is an equal and opposite reaction. 



Felt recoil is the results of Newton's second law, which deals with acceleration. and states when a force acts on a mass, the greater the mass the greater the amount of force needed to move the mass. 

A 30/06 cartridge propelling a 200 grain bullet produces an specific amount of energy depending on the speed desired for the bullet. An equal amount of energy is expended rearward into the gun. The heavier the gun the more energy it takes to enact newton's first law (not A exact quote)
An object at rest remains at rest unless acted upon by a force greater than it's own.

I will use a 458 Winchester magnum with a 500 grain bullet because I happen to shoot one and know it's recoil in foot pounds without going o the books for specifications.

a 458 win mag delivers 58 foot pounds of recoil energy. shooting a 5 pound gun (Roughly) 53 pounds would be delivered to the shoulder of the shooter. The same cartridge fired from a gun weighing 10 pounds would deliver only 48 pounds of felt recoil. 

Mathematics never very only factors in the equations.


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