richard-cabesa avatar image

Wrong system voltage . How did he get here?

I have a friend that had camper van built by a "professional" I use the quotes because I don't know his actual qualifications.. My qualifications are slim but I do have a system that I put together myself with six Battle Born batteries, Three Victron solar charge controllers, Orion 12/12/30, and a BMV712.with 800 watts of solar. It;s has been running close to three years and I am pretty familiar with set up and settings.

So to my friends system,. He was having problems right after he picked up his van and asked me for some input as his builder is three hours away.. His system is a 12/300/12 MultiPlus, 150/60 Smart MPPT, and an Orion12/12/30. 600 watts of solar and ONE 300Ah battery.

First thing I spotted was several blown fuses in his DC panel. OK, what is blowing those?

Second, he was never instructed on use of the BMV712 or that there was an app for his phone. I got him started on that.

The next thing I found was that the MPPT was pumping 40 volts to the 12v battery!!!! Whoa

Clicking the Battery tab in the app showed the battery system voltage as 48v. So this is my question.

How did the controller select 48v for the system? All of mine automatically selected 12 v when first connected.

Turns out one of the blown fuses was to the $3000 refer. Fried brain, has to be replaced.. Not sure on the others as nothing was labeled.

There were no switches to shut off the solar or the Orion so I just pulled the battery cable and sent him back to his builder.

dc system
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1 Answer
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

This can happen if the MPPT is connected to PV first.
Or the installer tested the MPPT first on a 48V system and forgot to set it back to 12V?!

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