Ground rod question

[RSL]

Are any of you running 12v fencers without solar chargers? I need something temporary to do less than five miles total - a clean area and it shouldn't have to shock through any grass or brush. I was thinking about using a 12v and just keeping a spare battery charged up. Any advice for an application like that?

We have run several like this with little bee fencers (parmak makes them) for years, but have converted most of them to a little 15W solar panel on the battery for under $100.
A big fencer can take a lot of battery...

 

[RobertMac]

Think about circuit of a electric fence...it starts at one terminal of the charger and ends at the other terminal. A pulse goes down the hot wire, through the animal, through the ground back to the ground rods, and ends at the ground terminal. The physical characteristics and moisture content of the soil between the rods and the animals hoofs is a much larger factor than any treatment at the rods. If I'm not mistaken, Gallagher recommends galvanized rods because they are less reactive with the soil...less corrosion that inhibits electron flow. Ben can correct this if I'm wrong...maybe stainless steel rods would be best.

The best description I saw was the ground rod system as an antenna. The bigger the antenna, the more signal (electrons) it will collect which equates to more shock through the cow.

 

[Ben H]

Rust blocks the flow of electrons. DO NOT use rebar. I think galvanized is fine, no need to spend money on SS. Hot dipped Galv is good stuff, maybe actually better then SS?

Don't mix copper and galvanized, it will cause electrolysis and ruin your connections.

 

[Texan]

Thanks for the input, everyone. I might try a used 12v tractor battery that probably won't make the winter starting a tractor. Maybe I can get a week or two out of it between charges since I'm not going to have but a couple of miles of fence that should be fairly clean.

 

[Ben H]

Jim:
Car batteries are designed for one thing and one thing only - delivering a bunch of power for a very short period of time. Said time is measured in seconds, not minutes, hours, or days.
I have been living "Off the Grid" for fifteen years, and can assure your readers that vehicle batteries can only handle 3-5 complete discharges before they are useless, i.e., after but a few discharges they cannot be recharged and expected to hold said charge. Ergo, they are the wrong choice for any task where discharge exceeds the constant charging input into the battery. They will not last, and the monies and the time procuring and cabling such will have been wasted.
If one intends to utilize batteries and a charger of whatever source to power lights or equipment of any sort, only use "Deep Cycle" types as the plate construction used in these is designed for multiple deep-discharges. The number of discharges varies given the size of the battery itself, and can range from as few as 100 to well over 2,000. Yes, in the case of batteries, size matters.
Another little hint: When engaged in the mathematics of power generated in relationship to end use, whether from solar, microhydro, wind, or fuel powered generators, remember that when using a battery to "store" generated power, factor in a loss of 6% of the power produced due the requirements of the chemical reaction in the battery. Period. And never forget that "Volts X Amps = Watts". If you don't model your production and usage with these numbers in mind, say goodbye to your batteries.

http://www.survivalblog.com/2009/11/how_to_capitalize_on_urine_car_1.html

 

[Liveoak]

Jim:
Car batteries are designed for one thing and one thing only - delivering a bunch of power for a very short period of time. Said time is measured in seconds, not minutes, hours, or days.
I have been living "Off the Grid" for fifteen years, and can assure your readers that vehicle batteries can only handle 3-5 complete discharges before they are useless, i.e., after but a few discharges they cannot be recharged and expected to hold said charge. Ergo, they are the wrong choice for any task where discharge exceeds the constant charging input into the battery. They will not last, and the monies and the time procuring and cabling such will have been wasted.
If one intends to utilize batteries and a charger of whatever source to power lights or equipment of any sort, only use "Deep Cycle" types as the plate construction used in these is designed for multiple deep-discharges. The number of discharges varies given the size of the battery itself, and can range from as few as 100 to well over 2,000. Yes, in the case of batteries, size matters.
Another little hint: When engaged in the mathematics of power generated in relationship to end use, whether from solar, microhydro, wind, or fuel powered generators, remember that when using a battery to "store" generated power, factor in a loss of 6% of the power produced due the requirements of the chemical reaction in the battery. Period. And never forget that "Volts X Amps = Watts". If you don't model your production and usage with these numbers in mind, say goodbye to your batteries.

http://www.survivalblog.com/2009/11/how_to_capitalize_on_urine_car_1.html

Good article Ben! I too tried the car batteries and didn't have much luck with them. Solar wasn't always dependable but the deep cycle batteries did the trick. That and properly set ground rods. Personally, I can't stand electric fencing unless it's away from trees. Falling limbs can short them out in a heart beat and once cattle learn they can get through then it's a constant battle. One of my neighbors has had real good luck with electric and he only sets out one wire about 2 1/2 -3 ft off the ground. Rarely has any problems ( no trees ).

 

[LaramieRiverWrangler]

Thanks Ben for the excellent information on grounding. I can tell you have been at this for quite a while. The more I mess with this electric fence the more I learn. We have a lot of vegetation issues on these hay meadows, along ditches, and the riparian area of the river. Like someone else said grounding may be more important than power.

 

[Texan]

Thanks for the info on the car batteries, Ben and Liveoak. I might have to rethink my plan. If I'm going to have to invest in two marine batteries, I might be better off just going with the solar charger. I'll just have to put the pencil to it. Thanks.

 

[Ben H]

I don't know what kind of solar charge you're looking at, but the smaller ones come with gel cell batteries, the large one like the B100 and B200 are a panel mounted on the battery box and don't come with the battery. It doesn't make sense to pay the shipping on something that heavy when you can buy it locally. So make sure you factor weather or not you need a battery separately.

I'll be 30 Wednesday, I started building HT fence when I was probably in Jr High. We took over the area dealership for Gallagher, I built and repaired a few fences for people in High School. Sheep, horses and cattle. I kind of didn't do much of it while I was in College and working out of State after school. Now that I'm back home I've gotten back into it, mostly for myself. I have re-learned a lot of things that were wrong and picked up a lot of tricks. I would love to get over to New Zealand sometime and learn from the real professionals. There is a need for a contractor in the area, but I have a decent paying job with benefits that doesn't allow me to take on any more work. The fencing could work if we didn't have frozen snow covered ground for so many months. It would also work pretty well to allow me the flexibility with my grazing. With this economy and uncertainty of where it's going I'm just trying to take in what I can. I don't know if the people are going to see the light with grazing before it's too late or not, one of the most frugal dairy farmers in the area is loosing over $2K a month. If he's not making money, nobody is. The farm is surrounded by lots of fields, could be a nice grazing dairy.

A classmate of mine from Cornell is now working in a soil conservation district in NY, he said that back in 2003 or 2006 the NY Dairy Farm Business Summary showed the profit per cow was double for grazing dairies. They had to go back and change the formulas. Can't be having something like that get in the way of all the research dollars to support Cargill and Monsanto inputs.