I have an array of 6 327W panels. They are listed as 64.9 voc and 6.46 lsc. I’m planning to hook them up to a 48W system. At 3 parallel/2 series that would be a 129v array that could deliver 32.3A. My plan is to use a BlueSolar MPPT 150/35.
As a backup I’d like to be able to run this with a 12V battery. I realize the solar array would be over paneled for the charger while using 12V, but two panels has not been enough to fully charge my battery on cloudy days. Could 4 or 6 of these panels at 12V damage the charger? If so, what would be the best size charger to sufficiently handle the full array in 12 and 48V configurations?
It will be fine for both systems as you don’t break the 2 rules (max voc and max isc) even leaving it at 3s 2p for both.
Just be careful when changing over the batteries and set the output voltage on the mppt correctly each time. And have a good way to disconnect both pv array and battery bank disconnect. There should never be electrically exciting moments.
But like you say a total waste of an array at 12v as the mppt will only ever put out 25amps. (6x327watts = 1962watts) Would be 163amps at 12v so yes a larger mppt would be more ideal. You definitely wont have to worry about not reaching a full charge.
But like you say a total waste of an array at 12v as the mppt will only ever put out 25amps. (6x327watts = 1962watts) Would be 163amps at 12v so yes a larger mppt would be more ideal.
I’m not understanding how these calculations are arrived at. Wouldn’t the 150/35 be able to put out 35amps (~420-460W) at 12V?
Also, I raised this question because my current Asian charger is rated at 390W but the manual gives a maximum array size of 580W at 12V, even though with a max voc of 92 for the 30A charger I should be able to hook up 4 panels in parallel to get 64.9V and 25.84A for 1677W. Is Epever being overly cautious by limiting wattage at lower volts, is Victron built to withstand more excess current?
