(2) 12V Solar Panels....Series or Parallel?
I have (2) 140w 12V panels. The Bogart Engineering solar controller can operate on 12V or 24V input. Is there any advantage or disadvantage to wiring the panels in series for 24V rather than parallel ...
Forum Discussion
Not so fast! :) I posted my good results with 24v panel and 24v batts using both MPPT and PWM. 24-24 was the same amps for both and that beat the amps using 24-12 MPPT (controller efficiency suffers with the buck conversion)
Two 12s in series at 36 cells each would also solve the limitation with 24v and a single 60 cell panel that can arise in some scenarios.
However, getting 12v to the rig from the 24v batts is an "issue". There are several ways to get by that too, but you need to start out with the 24v planned so you buy a 24v inverter, a 24v charger for when solar is no good, and some kind of 24-12 converter. (Although you can run your existing 12v converter from the 120v inverter on the 24v bank, if the solar supply is plentiful in daytime to keep up with nighttime 12v use as well)
I liked being able to run the lower cost 24v panel with the lower cost PWM vs expensive MPPT or expensive 12v panels with the low cost PWM. You can't find low cost 12v panels and low cost PWM anymore sadly.
Two 12s in series at 36 cells each would also solve the limitation with 24v and a single 60 cell panel that can arise in some scenarios.
However, getting 12v to the rig from the 24v batts is an "issue". There are several ways to get by that too, but you need to start out with the 24v planned so you buy a 24v inverter, a 24v charger for when solar is no good, and some kind of 24-12 converter. (Although you can run your existing 12v converter from the 120v inverter on the 24v bank, if the solar supply is plentiful in daytime to keep up with nighttime 12v use as well)
I liked being able to run the lower cost 24v panel with the lower cost PWM vs expensive MPPT or expensive 12v panels with the low cost PWM. You can't find low cost 12v panels and low cost PWM anymore sadly.
