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· Senior Pirate
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.... Also I'll need a 24v to 12v converter for power to the house, any suggestions on that?
Why?

You now have two group 27 batteries in series right? What's powering your house requirements now? I would have tapped your "house" across one of the two batteries as requirements would be minimal on a 22' boat.

Back to your original concept, a 60 watt panel will provide less than 4 amps at 18v. The MPPT controller will shift the voltage to 24v but the current drops to 2.5 amps. A group 27 battery is roughly 90 amp hours. You have 2 of them. You're not supposed to draw them down more than 50% ... so you're looking to recharge 90 amps. 90 amps/ 2.5 amps per hour= a very long time. But wait, there's more. The output of the panel is rated at 60 watts set exactly 90 degrees to the sun at all times, and in strong sunlight... no clouds, no shadows, In reality the 2.5 amps I mentioned above will not be seen. You probably could count on just 2 amps per daylight hour of sunlight, meaning it would take almost 6 full days to charge the batteries back up.

How's that going to work?
 

· Senior Pirate
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That's how it's setup now. Is that OK? It seems kind of half-assed to me....
Sure it will work. In time you discover that one of the batteries will bite the dust before the other does. However, make sure the MPPT controller you buy has different charge cycles. The one I have equalizes the batteries I think every two weeks. It just happens, and I don't worry about it. This is important for extending the life of inexpensive batteries to 4-6 years or even longer at your latitude. Here in Florida batteries fail faster it seems than any place I've ever been!!
 
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