question

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Large difference between solar blanket voltage output and Victron dashboard

Hi, I just purchased a Victron 75V/15A solar regulator to use with a Baintech 120 watt solar blanket to charge the second battery on my car.

I've been unable to get the unit to charge yet (cloudy day and not certain getting 5V above battery voltage) - what I find confusing is that my multimeter tells me the solar blanket output is around 17-18 volts yet the Victron bluetooth dashboard says the output is anything from a few volts up to about 12.5 volts (never above 13 volts)?

My multimeter is pretty new and gives expected results when I put it on the car battery etc.

Any insights would be appreciated

Thanks in advance

Wayne

MPPT - Solar Charge Controllermppt smart solar
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2 Answers
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alan answered ·

Are you measuring the solar blanket when its only connected to the multimeter?

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wayne1015 answered ·

Hi Alan, yes I am - I'm disconnecting the Anderson plug that connects the solar blanket to the Victron controller to take the reading.

Wayne

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Your measuring the open circuit voltage of the panel, the working voltage will always be lower.

Wait for full sun, the open circuit voltage will probably be around 21v.

Hi Alan, excellent - thanks very much.

Wayne