Solar charger controller needed?

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Solar charger controller needed?

Postby jonesnforcampin » Mon Jul 10, 2017 11:04 pm

Hey all, I don't understand really anything about how batteries or solar chargers work, so please excuse my extreme ignorance. A while ago we bought a tiny 1.5 watt solar battery charger, do we really need a charge controller? Is it really going to produce enough power to damage my two 6 volt batteries? In all the reviews people say nothing about using them, but in reviews for a 13 watt charger a couple people mentioned using charge controllers.
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Re: Solar charger controller needed?

Postby MtnDon » Mon Jul 10, 2017 11:13 pm

Your batteries will hardly notice 1.5 watts. That amounts to 1.5 watts divided by 12 volts = 0.125 amps. That's hardly even a decent trickle charge. Is it really 1.5 watts? Not 1.5 amps? Even then it would only be 1.5 amps under full sun and that is only going to occur for a few hours on a sunny clear day if the panel is pointed in the right direction. I'd say "no worry".
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Re: Solar charger controller needed?

Postby daveesl77 » Tue Jul 11, 2017 8:06 am

I agree with MtnDon, I think you need to review the actual size of the solar panel. Only thing I can think of that would be 1.5 watts would be like a solar garden light. 15 watts is a small panel. At 12v that would be just over 1 amp at full sun. think of a charge controller as more of a voltage regulator. Such as a small panel, unloaded, might put out 17 volts and 2.5 amp. The controller limits this to say 14 volts. PWM controllers are cheap, but not as efficient. MPPT are way better, but more expensive. When my grandson went to Alaska with the Boy Scouts, I got him a small 10 watt, folding charger for his backpack. It was really little, but it kept his camera batteries charged.

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