Originally Posted By: MDinana
My off the grid plan is to take my dinky lawn solar powered lights and use them to recharge my batteries. And if people aren't home, borrow their lights too shocked

Slightly OT, but thought I would chime in as I've been testing this exact setup for the better part of a year.

My practical experiments indicate that the only way to make this work is to bypass all the internal circuitry in these lights and hard-wire them directly from the solar panel to the battery terminals. The cheapies I'm using (including some tossed in the dump, NiCd batts and all -- grr!) produce a little over 4 VDC directly, though at a such a miniscule current that you can't really overcharge.

I find that they will effectively charge low-capacity NiMH cells (in the 1200+ mAh range), but are barely enough to maintain high-capacity cells (2500s) at their existing voltage.

Bottom line: with 2-3 of these rewired units plus cheapo NiMHs ($1 ea.) and a decent 1-AA LED light, you have more-or-less perpetual light as long as you have sunshine. Naturally, YMMV.

Edited by dougwalkabout (04/24/11 03:57 AM)