Solar Charge Controller
Looking at solar and seeing different options for controllers. What's the difference between PWM and MPPT?
Forum Discussion
Doesn't have to be "hot climate" to lose amps with MPPT due to panel temperature over PWM in same situation.
Here, east side of Vancouver Island, by the sea, cool breezes, with 230w tilted up (no heat trap underneath) and MPPT, ambient at 16C, I was getting 15.5a to battery, panel temp was 44C. (measured with IR looking up at white part under a tilted up panel)
At ambient 25C nice summer day for here, panel temp now 51C and amps are 13.5 instead of 15.5. (PWM would be 14.5) So we have gone from being 1 amp more than PWM in the Spring to being 1 amp below PWM in Summer.
Some solar info dug up by Googling, says you lose about 10% with MPPT when panel temp is 50C, so my 13.5 vs 15.5 comes out in ballpark where 2/15.5 = 13%
Hate to think what the results would be in a "hot climate" in the summer :)
BTW, the panel specs are for panel temp of 25C standard test conditions. How can they get the panel temp that low? Ambient would be near freezing to get panel temp 25C it seems.
Here, east side of Vancouver Island, by the sea, cool breezes, with 230w tilted up (no heat trap underneath) and MPPT, ambient at 16C, I was getting 15.5a to battery, panel temp was 44C. (measured with IR looking up at white part under a tilted up panel)
At ambient 25C nice summer day for here, panel temp now 51C and amps are 13.5 instead of 15.5. (PWM would be 14.5) So we have gone from being 1 amp more than PWM in the Spring to being 1 amp below PWM in Summer.
Some solar info dug up by Googling, says you lose about 10% with MPPT when panel temp is 50C, so my 13.5 vs 15.5 comes out in ballpark where 2/15.5 = 13%
Hate to think what the results would be in a "hot climate" in the summer :)
BTW, the panel specs are for panel temp of 25C standard test conditions. How can they get the panel temp that low? Ambient would be near freezing to get panel temp 25C it seems.
