Yet another example of Mono vs Poly where you lose amps with Mono (with 12v and PWM)
You get Isc with 12v and PWM so you want the highest Isc per watt of panel or dollar per amp. dollar per watt is no good if the amps are lower, so you should do dollar per amp with 12v and PWM.
Mono spec quoted above vs 150w Poly panel (Sun brand)
Voc 22.5/21.0
Isc 9.05/9.58
So you lose half an amp with the Mono because its Voc is jacked up higher. So two 150s with the Mono will cost you an amp.
At 300w its 18.10/19.16
But now you have to do it in dollars per amp to see which is the better buy.
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In series you add the voltage and the amps are the same.
In parallel you add the amps and the voltage is the same/
MPPT wants high voltage to work with so series is optimum for that.
If in series you must have MPPT to get back to 12v for the batts,
PWM is already at 12v, so it just takes the total Isc rating amps and that's what you can get to the battery.
Whether the MPPT will do more amps to the battery than the PWM would depends on the temperature. If cool out, it will do a little better, but if hot out, it will not do as many amps as the PWM.
You have to know what it will be like when you are camping when and where before you can decide that. Money comes into it somewhere too. 24v panels cost less than 12v panels usually. But the MPPT controller costs way more than the PWM controller. there is a break even point depending on prices. Prices vary wildly all over the map, so it is impossible to say what would work best for you without knowing what YOU know. So it is up to YOU! :)
