

| Subject: | Re: Solar controller question..semi off topic. |
| From: | Loren Busch |
| Date: | Wed, 17 Apr 2013 08:47:50 -0700 |
RE: Solar Panels and Controllers Don, the subject has been coverd by the reponders up till now. But let me add this. You mentioned connecting the two mismatched panels you have in series. They MUST be connected in PARALLEL! As for controllers I have and have used two different controllers, one conventional and one MPPT (cheap, out of China off eBay). Both work fine and I've used them both with two 50 watt panels deployed outside the Westy and now with a single 120 watt panel on the roof. The difference I've seen is that the conventional controller goes up to about 14.4 volts in good Sunlight and the MPPT controller stops at 13.3 volts. 14.4 volts is about what the batteries see from the alternator while the 13.3 volts is the normal 'float' charge on a lead acid battery. I my case I'm using an AGM battery for the aux and they like to see about 14.4 volts for charging. So I'm using the conventional charger most of the time. Plus it's more reassuring to see the higher voltage on the meter all day :) Note that I am probably not pumping as much current into the battery at any moment with the conventional controller but the battery is topped off before noon on most days with Sun.
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