question

jadman avatar image
jadman asked

Smart solar 75/15 battery voltage showing considerably higher voltage on app

Multimeter shows 12.57 at battery and mppt terminals. App shows 12.74. I have checked the fuses and tried shortening the wire between mppt and battery. I am running a renogy 200w suitcase where I swapped the pwm controller out for the victron. I have a 20’ extension between the panels/mppt and the batteries.
thanks in advance for your input

MPPT Controllers
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1 Answer
Jesse avatar image
Jesse answered ·

That's a small and very realistic voltage difference though 20 feet of wires, even with a tiny current. Also within the margin of error for many cheaper multimeters.

It's generally preferable to have the MPPT positioned on the batteries and run longer lengths of solar wires.

The bluetooth voltage temperature monitors will fix this difference, but wont adjust for losses involved in your setup. The design of these mobile panels is always flawed - controller should never be next to the panels.

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