Here’s a 10 watt photovoltaic charger with a 12 Ah battery. You can do quite a bit with this baby. It’s based on a Popular Science DIY article from July of 2008. Let me know what you think. Jocelyn Cohen. Here are the specs:
10-watt photovoltaic (PV, aka solar-electric) panel:
Voltage: max. power 17.6V, open circuit 21.6V
Current: max. power 0.57A, short circuit 0.61A.
Pop Sci used a 5-watt panel, probably to keep costs down, but if Im bothering to build it, I want to get more out of it! The charge controller can handle an even bigger panel, too.
battery:
12 amp-hours
4 amp charge controller:
I love this elegant little thing. Here is the spec sheet from the manufacturer: http://www.vellemanusa.com/downloads/6/sol4ucn2gbnlfresdpl.pdf. The charge controller keeps the battery from overcharging or discharging too deeply, both of which can ruin the battery.
meter:
The Pop Sci article used a 10A meter, which doesnt do much when the panel is only rated at around .6 amps! If about .7 is all youre going to get at peak power, then the 1 amp meter will do the trick.
In the video youll see that I used a cheap multimeter to measure current for now, but Im going to add an analog panel meter like this one between the panel and the controller. Im also going to add a meter or two between the battery and the load to put numbers on what this baby can actually do.
I got connectors at Radio Shack.
Post time: Jul-04-2017