Battery bank voltage

tomsuntomsun Registered Users Posts: 8 ✭✭
I have two Rich solar 100 watt panels and 1 - 12 volt 35ah battery, (probably going to purchase a 2nd battery), and a epever 2210 mppt controller. 
I mostly just power a couple of 12 volt led bulbs drawing 10-11 watts each.
I'm not sure how to wire the panels and batteries, I really want to stick with a 12 volt system for effiency and simplicity. 
So do I need to stay with parallel wiring with the panels and the batteries to keep 12 volts? 
Also, would one battery be sufficient or will I fry it with the two panels?
I'm in southern Wisconsin, so not a lot of sun. 


  • EstragonEstragon Registered Users Posts: 4,495 ✭✭✭✭✭
    Check the maximum input voltage spec for the controller, but assuming it actually is mppt (some claim to be, but really aren't) I'd wire the 2x12v panels in series.  The mppt should buck down to charging voltage for the 12v battery.  In some conditions (hot panels and cold battery), it may not get enough voltage to charge properly in parallel.

    The panels only produce enough current to supply loads including charging.  They might produce something like 12a with a larger load.  Depending on the battery, it might take 1/2 that.  Don't know about your controller, but some can be set to explicitly limit maximum charge current.

    If you did add a second battery, you'd wire it in parallel to stay at 12v nominal.
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • mountainmanmountainman Registered Users Posts: 439 ✭✭
    The epever 2210 is a 100 volt 20 amp controller. It can take 3 panels in series. Agree on 2 100 watt panels producing 10- 12 amps. What battery chemistry lead acid or other?
    2kw array 6 345 q cells  make sky blue 60 cc
     6 230ah GC @36 volts 
    18 amp accusense charger. 3650 champion 
  • tomsuntomsun Registered Users Posts: 8 ✭✭
    AGM lead acid. 
  • SolfyrSolfyr Registered Users Posts: 22 ✭✭
    2 pieces of 12 Watt light bulbs x 10 hours = 240 Wh .

    35 Amphours Battery capacity x 12 Volts = 420 Wh .

    You defininetely want more battery capacity .
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