Originally posted by Podinaroundbc
We just bought two 40 watt panels. I would like to connect them together. What is better? In series to up the wattage or in parallel to up the amperage? |
Whether you wire them in parallel or series, the maximum watts will be 80. What changes is the volts and amps. Wired in series the volts double and the amps stay the same. In parallel the volts stay the same and the amps double. In both cases amps X volts = power.
How you wire them up depends on what kind of charge controller you have. If you have a Pulse Width Modulating (PWM) controller on each panel, I would wire them in parallel. That way each controller would see battery voltage and adjust amperage appropriately.
If you have a Maximum Power Point Tracking (MPPT) controller the panels can be wired in series to keep the same amps but doubling the voltage. To do this your controller must be able to handle the increased voltage. In this method the controller should be near the battery and the panels could be at some distance from the camper. You could also wire the panels in parallel with a MPPT controller.
As an example I have a MPPT controller using two 24-volt panels wired in parallel. The operating voltage is 36 volts. The controller converts that voltage to what the 12- battery needs for charging. If I had two 12-volt panels (18-volts operating) I could have wired them in series. The controller would make the necessary voltage changes to charge the battery.
However you decide to connect them, be sure to follow the directions that come with your charge controller. You must have one of these to avoid destroying your battery.