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neoneddy avatar image

MPPT Derating / Throttling - Can PV voltage affect heat generated?

I'm trying to solve my MPPT Derating issue, I have 2600 watts of panels connected to 2x 100|50 Blue Solar Charge Controllers. The panels are in 2 groups of 4 in series parallel pairs with a voltage of around 80 volts. My battery bank is 24 volts.

I have a fan on the charge controllers, bad news is they are stacked, so the hot air form one tries to cool the next, but they both throttle. I also have ventilation of the charging / inverter / battery bay, but it still throttles. I see they derate at 40c, so I hit that often.

I'm wondering if there is any advantage to going to all parallel on my panels? Is excess heat being generated by stepping down 80v to 24v vs 40v to 24v ?


MPPT - Solar Charge Controllertemperature
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1 Answer
Alexandra avatar image
Alexandra answered ·

@neoneddy

There is not really an advantage to changing the configuration of the panles as watts are watts.

Each charge controller will be processing 1200w of power (50A x 24V). So that's the heat it has to deal with. Regardless of how you configure the panles it will work to charging at the 50A unless you set the output a bit lower in software.

You can try space your mppts away from the surface they are mounted on for better air flow or attach it to the vehicle skin (some even use heat sink paste for better coupling) so that the heat is taken away by the body of the vehicle as well. Or mount them on aluminum rails. But definitely if you are able get some more space between them.

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