Using Car Batteries in electric fence units

Goldpine reckon I can use normal car battery but the battery geeks reckon I should use a deep cycle battery as it will last longer and give a better zap right to the end of it's charge.

Who uses what and which is better? As far as I was aware most people just use normal car batteries? Don't particularly want to spend a couple of hundred on two normal car batteries if I then have to upgrade to deep cycle cause they are crap. (PS, will get two so one can sit on charge while the other zaps the moos)

What the geek says may very well be correct but I used to use a couple of old car batteries picked up from a car wrecker for about $20 each and they would last for years, to hell with spending a couple of hundred dollars!!!!!!!!

Same as Rod. A battery that won't start a car will run a fence for months and will be good for several years usually.

A couple of old batteries from the wreckers and a small charger should set you up.

Cheers,
Ronnie

Even better, a reasonable size car battery and a solar panel to charge it

Hi Dr Vee, technically a deep cycle battery will be what is called for but we live in the real world and life is not perfect.

If you know a friendly auto electrician see about getting a couple of truck or tractor batteries that are not quite up to starting the large diesels but still have a bit of go in them. Use these but don't run them dead flat. Set up a swap over regime and follow it. Say every Sunday or some such plan.

If you run them flat they will fail fast.

There are a lot of myths about electric fencing. Keep in mind that the unit is designed to deliver a certain amount of energy into the fence each pulse. As the battery goes flat there may not be enough oomph to fully charge the capacitors in the energiser but this will be the case if you are using a deep cycle battery or an automotive type. All that will happen is that the deep cycle one will last longer between charges (greater capacity) and give you more charge/discharge cycles before failing. It won't give you more zap on the fence if it flat!

I also used an old car battery (wouldn't start my car if left overnight) and it lasted for a couple of years, gave a good zap too.

Every couple of months, my Dad had to recharge it for me, and I don't know if you're meant to or not, but I covered it with an old nail box to keep it out of the rain (and to stop goat mouths from fiddling with it).

Yep, we've got a few old second-hand car batteries (kept them when we changed the car batteries) and each of them will last a month on a portable electric fence unit. We test the output after a month and change them over. We can then recharge the previous battery and there's less worry about the battery not lasting, like the small energiser batteries. They were only 4 x D size batteries and were only lasting a week or so.

I have 2 reasonable old car batteries with a small solar unit for 1 unit.. I give them a good charge every 6 weeks or so. I have 1 unit with a new battery this last for ages. They have to be better than half charged to deliver the zappo

Yes as said old car battery is the answer, we've done it for years. True as PG. put it in an ideal world..................... .Have never used a solarcharger on one but sounds a great idea to try must do:)

Same as us. We have several and swap them and recharge. We got them at a place where they recondition old batteries and cost about $25. They seem to last for years.

For the cost of a new deep cycle battery you can buy the solar panel to hook up to the old truck battery so that you never have to charge it. I had a system like that running for a couple of years before I had the power connected.

Go to a car wrecker and you will get a good battery for nicks

I had my battery unit housed in the shed and with that it was near the power point. You can get a battery charger that turns itself off when the battery is charged and then turns back on when the battery needs charging, I used this for ages, I didn't have to remember to check the battery and it was like having a mains units (almost). The charger is $60 or $70 (from memory) and can be got from a shop like repco, maybe, the red shed or super cheap.

Yep a car battery that is long past starting a car (and therefore = free!) will work for years on an electric fence. But good point from powerguy to keep them recharged before they go dead flat. I always forget to do this and only charge them about every few months but so far I've only killed a couple by running them dead flat from not keeping up with a regular recharge regime. Having a good earth affects the zap rather than the flat-ness of the battery. When they start to go flat I find the pulse gets much slower, but each zap it manages is still just as much zap. (Hint from experience: if the pulse has got much slower than it should be then they are not far off dead flat and will probably die the next day!). []

Jo-Otago;245682 wrote: Having a good earth affects the zap rather than the flat-ness of the battery. When they start to go flat I find the pulse gets much slower, but each zap it manages is still just as much zap. []

Yes, two points. Earthing is critical, especially in dryer weather but I am sure this has been covered in an earlier thread.

The energy and timing of the pulse will depend on the energiser you have. Some are voltage triggered pulses, some are timer triggered and some use both. The ones I have use both which means the pulse will gradually take longer to trigger as the battery goes flat because the voltage rises more slowly but when it is so flat that it can't reach the full pulse charge it will trigger after a certain time anyway. This ensures that whatever is there goes out but if the battery is very flat the damn thing can be sitting there beeping away and putting nothing on the fence!