Looking for advice on mppt controller purchase. Connecting 2 - 400 watt solar panels (each 400 watt- 40 v/10 amp max) to 4- 100 amp/hour batteries. Don’t want to over build or spend.
Thanks
On our 24V system, we used one 75/15 per 425W panel for shading reasons, 4 panels total.
The 100/50 will be the best. You will get about 720W max charge on a 12V system. You will get clipped a little on the 800W of solar you have, but I would expect you will only see about 600-700W max from 2x 400W panels. You can series-connect the panels or parallel them.
This depends on how the batteries are wired, ie 12V (4p), 24V (2s2p), or 48V (4s).
for 48V, a 20A or 15A controller, for 24V a 30 or 35A controller, for 12V a 60 or 70A controller is needed.
higher voltage systems 24,48V are usually better, and cheaper to build.
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Batteries are wired in parallel - so 12v battery system
Thanks