need battery charge controller?
 

Just installed a used driveway gate opener (Apollo) run on deep cell marine type battery with solar back up. The battery is new (deep charge marine type).

A few months ago, I picked up a old used PV panel at a yard sale. Wires were broken off on back and only had short stubs. Had my voltmeter in the truck and tested it (cloudy day) It was putting out some 0.5 A at about 20V. Based on that I offered $2 (they were asking $30) and got it. Just resoldered longer wires to the stubs . . .

Anyway, the label, on the back of the panel is almost illegible, but I suspect the panel is ~ 30 watts (18 inches x 22 inches).

The new deep cycle marine battery, fresh from the auto store, measured 12.5 V and today after one day of full sun is up to almost 15 V (one solar lead removed from battery when measuring this battery voltage).

I will open this gate only 2-3 times a day. With that little load, will I overcharge the battery? If so, what charge controller would you suggest to prevent this issue.

Thanks in advance.


Steve

eBay has small cheap pv controllers - I would look for one of the cheap ones with a high amp rating say 10 Amp to 20 amp so you have room for expansion down the road. the 10 amp ones are dirt cheap.

I've read some mixed reviews about some of the cheapest of the cheap generic (no name) charge controllers. I've got one, but I haven't hooked it up to see how long it runs before it cooks a component inside. I bought it to use on a 12W panel to keep my boat battery charged.

That said, I'm running a Morningstar sun saver 6 on my 20W 12V panel. My intent with this setup was to run my wifi router, I just didn't get to wiring up the router to it yet.

The Sunsaver 6 runs about $60 . . . Let me look again on ebay.

Steve