As some of you may recall, I wanted to build an electric fence controller, but some of the members here objected, so I scuttled the idea and bought one. It's a Zareba EDC5M-Z and is DC powered.

I want to use a 12 V lead acid battery to power it, and recharge the battery with a solar panel. Unfortunately, I can't find its exact specifications, and Zareba has so far balked at helping me.

What I need to know is what size (AH) battery is optimum for this controller when the battery is to be recharged with a 10 watt panel. I want the system to be continuously powered year round. I know there are lots of variables to be considered, but I am hoping there are some general assumptions that can be brought to bear.

The system is to be installed at approximately 35° north latitude, and will be less than 1/2 mile long. Weeds will not be an issue. The controller seems to put out about 48 pulses per minute.

Thanks.

 

It would help a lot to measure the current draw of the controller. It might change when loaded, so it'd be best to measure it in the field. But any estimate - like measuring current on the lab bench - would be better than nothing.

If your panel peak output is 10W, you might make a guesstimate that you'll get 4-5 hours of equivalent full sun each day. (Obviously, a researched estimate would be better. Maybe someone near you has a PV installation and would share results with you.) So that's 50 Wh per day. Figure losing half that in charging, discharging the battery. That leaves 25Wh/day available to power your fence. If it needs less than 25Wh/day, you've at least passed that hurdle.

But if you want 100% operation without fail, I think you have to design around the worst, slate-gray, two-week depths of January when you might only get an hour or two of charging per day at best. The battery needs to be big enough to coast through the worst possible period without suffering a complete discharge, which will shorten its life. I'm not sure where to find such data except to ask solar experts in your area.

 

The website doesn't state the power it consumes but it stated a battery would last about 4-5 weeks. They don't state the battery size but recommend a deep-cycle lead-acid battery. The value of those can vary widely but, assuming a smaller one of about 60AH, means the average daily consumption would be about 60Ah/30 Days = 2AH per day or 12 Wh/day.

It would be best though to measure the average power consumption, if you can. But since it likely takes a high pulse of current only when it pulses, it may be difficult to measure the average unless you have an oscilloscope.

You might also try contacting them to see if they can tell you what the average current draw is.

 

I do have an old 15MHz scope, but I don't know how I would set it up to measure kilovolts, which I expect to get from the fence controller.

 

I do have an old 15MHz scope, but I don't know how I would set it up to measure kilovolts, which I expect to get from the fence controller.

I'm talking about measuring current from the battery.

 

I'm talking about measuring current from the battery.

+1
Me too. Especially since power in HAS to be more than power out, and is likely much smoother over time.

 

Thanks for the input. Due to the non-responsiveness of Zareba, I returned the controller to the retailer, and will buy another brand that supplies more customer support of their products. When I get the replacement, I'll post again for help.

 

As an owner of live stock, I'd go spend the money and buy a Gallager brand solar fence charger. They are quality built and stand behind the warranty.