I have 2 solar panels, 100w and 125w. They will separately power one 100ah battery each. Can I parallel connect the 2 batteries for charging purposes or should the batteries separately go to the same 30amp charge controller to then charge my stuff? This is a 12v system. Thanks for any help.


1 Answer 1


I would connect the two batteries in parallel to the controller and the two panels in parallel to the controller.

Separating each panel / battery would need a second controller - then you may consider a method of supplying the loads from either battery with a changeover for backup.

  • \$\begingroup\$ Thanks, but wouldn't connecting the two panels that don't have the same wattage cause me to lose some of that wattage? \$\endgroup\$
    – ofrost
    Jul 17, 2017 at 10:54
  • \$\begingroup\$ Either use diodes or put the panels in series if the charge controller can handle the input. \$\endgroup\$
    – Solar Mike
    Jul 17, 2017 at 11:10
  • \$\begingroup\$ The panels in parallel won't "loose" the difference in power, it will all go into the charge controller. But blocking diodes may still be a good idea. \$\endgroup\$
    – Solar Mike
    Jul 17, 2017 at 11:31

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.