Link of studyConsider a MPPT when you get 24V panels over 200W each, or your whole solar panel setup is over 360 Watts total with 24V panels. Rogue MPPT 2024... $250
Consider a PWM charge controller if your panels are all 36 cell 12V design making 17-18V each at Max load, 22-23V unloaded. Solar 30 Adj Voltage to 15.0V PWM 12v/24v 30 amps max.... $29
No brainer, for me. Save the money on the controller and go buy another 120 watt panel, and still put some change in your pocket.
BFL13 did a comparison on MPPT vs PWM, do a search and read up what his real world findings were... He doesn't have a dog in the hunt for either brands.
Although not a direct comparison, you have to keep temperatures in mind when running MPPT's, they lose their gain when it gets hot, and provide less or no benefit then. If you camp spring, summer and fall, you should take that into account.
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