I’ve read all the documentation and think I understand, but to make sure, is there a max wattage that can be connected to a MPPT 250/70 in a 12v battery system?
asked
Max watts for a MPPT 250/70
2 rules NOT to break: Don't exceed the max input voltage (250) with your module open circuit voltage (Corrected for lowest temperature), and don't exceed the maximum Isc permitted by the controller. Apart from that, you will max out the controller at Iout (70A) X Battery Voltage (13.8 in a 12v system) - in this case 966W. You can connect more input power, this will give you more output on a cloudy day, and at the beginning and end of the day. typical would be 10 - 20% extra power, so with a 12v system and a 70A controller, a realistic max would be 1200W.
Thanx. I have four 320 watt panels, which yields 1280 watts if maxed out, which is probably rare. Will the additonal 80 watts (1280 - 1200) be an issue?
No. The Victron online calculator uses 30% over panelling. Guys living in low sun areas regularly high a high excess PV to provide adequate power in winter.
