Solar help... Mppt or PWM
Hi.. I recently got a new solar panel from somewhere... fell off truck... lol I know mppt is the way to go im mysituation but am asking for advice... panel 250 watts volts 30v. Wh...
Forum Discussion
lawrosa wrote:
I tested the volts at the leads. Showed 35volts and it was no sun and cloudy. Is this correct?
yes, the rated Voc (Voltage open circuit) is 37.7v in full sun, in low light it will be lower. Another test is the Isc (Current shorted circuit) at the leads. Set you meter to amps (this usually requires moving one probe to another 'hole'), in full sun you should read near 9A.
the morning star will temp compensate, hold absorption set point for some time and with a link to a laptop be programmable.
typical IV curve (1000 full sun, 200 very low light) of a 250 watt panel
ignoring effiency, PWM of 8.9A x 14v = 125 watts
MPPT 8.4A x 30 = 250 watts converted to 14v = 17+A
what's your daily usage?
