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Join Date: Jul 2000
Location: Houston, Tejas
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Originally Posted by jyl View Post
I have a little solar panel, leave it on the dash, plugged into cig lighter. Didn't work. Grrr. Maybe I should put a slightly bigger panel on the roof and hardwire it. How big a panel would you go - want to be safe from overcharging.
Does your car cigarette lighter work with the ignition off? 5-10 Watts should do it. A 0.5 amp trickle charger makes maybe 72 Watt-hours per day. A 10 Watt Solar panel will do ~50, depending on location.

Lead acid batteries lose ~3% per month. Even a tiny solar panel should keep it topped up. Check to make sure there isn't a relay which shuts off the outlets when the ignition is off.
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Old 09-04-2017, 09:18 AM
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