Portable (suitcase) solar "install" question
I've gone back and forth on solar panels on the roof or portable. Well, due to a tight budget, portable is the only way I'm going to get solar for now and it makes sense for me to try it out 1st as we...
Forum Discussion
"Do I use the 17.8vpm instead of 12v for the drop calculations? If yes, then I'm guessing I'd be well above the 12-14+ volts needed? "
With 12v PWM, panel voltage is the same as battery voltage except for a bit of voltage drop, so figure between 12 and 15 as it rises during the day. Use total panel rated Isc as your "expected amps" to go with the voltage in the tables to pick your wire gauge.
Eg a 100w panel will be 6 amps so two in parallel will get you 12 amps (and more of a voltage drop with the higher amps) You might add a panel later so get wire now to allow for that, and also a high enough amp controller--That Grape 40 is an excellent choice with its high amps, features, and costing no more than many lower amp ones.
Again, Vmp is only for MPPT controller calculations.
With 12v PWM, panel voltage is the same as battery voltage except for a bit of voltage drop, so figure between 12 and 15 as it rises during the day. Use total panel rated Isc as your "expected amps" to go with the voltage in the tables to pick your wire gauge.
Eg a 100w panel will be 6 amps so two in parallel will get you 12 amps (and more of a voltage drop with the higher amps) You might add a panel later so get wire now to allow for that, and also a high enough amp controller--That Grape 40 is an excellent choice with its high amps, features, and costing no more than many lower amp ones.
Again, Vmp is only for MPPT controller calculations.
