Forum Discussion
MrWizard
Jan 20, 2015Moderator
The part in the reference that has PWM equal or almost equal to MPPT within that panel temperature range never has PWM doing more amps to the battery than you would get with MPPT. Yet at 25C ambient, and 51C panel with 230w I get more amps to the battery with the PWM 14.5 vs 13.5 amps.
In the example above 14.5 is a 7.4% above 13.5 , in this case in favor of PWM
If you take out 50 amp hrs at 12.5v for 625 watt hrs
And put it back at 50 amp hrs at 13.8 about 782 watt hrs,
There is a direct correlation , this is the POWER needed for the recharge
And everybody is ignoring the power used during the daytime while the charging is going on, which is more power to be generated by the panels
As PT suggested, a proper test would be the same two panels used PWM then again as MPPT in series
Also a fixed load will always generate the same amount of power used regardless of the controller
You need a load such as batteries that are at a known SOC , so low as to be able to accept all power generated, then see which system generates the most power over the period of Sun up to Sun down
Almost impossible to do with batteries
I would suggest a parallel string of 12v dc light bulbs greater than the expected wattage of the panels
These will actually glow a little brighter and use more power as voltage goes up, no batteries, no inverter,
Put an amp meter or watt power meter in series
Read the total power generated , lighting the bulbs..Sun up to Sun down
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