CA Traveler wrote:
Doubtful that a serial or serial/parallel setup is practical but it depends... So your best option is 4 parallel panels in which case there is no MPPT advantage over a PWM CC. But you already have the MPPT CC.
Each panel should have a fuse (15A) in the combiner box. Otherwise a short could cause excessive heating from the other 3 panels.
I must take a small exception to the above comment. In full sunlight, even with parallel panel wiring, maximum voltage out of the panels will be around18 volts.....about 4 volts more than needed even for bulk charging the batteries. His MPPT charge controller will be able to convert that extra voltage into extra charge current; a PWM charge controller won't.