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astrayan avatar image
astrayan asked

MPPT 100/50 bluetooth VE network voltage wrong

I've got three Mppt 100/50 working together using the VE network, and I think it's an improvement against letting them do their own thing. I think the end point charge below 6A is more stable, also cloudy charging below 36W seems stable.

The problem I have is that the network seems to use arbitrary parameters from the three controllers. I make sure they are all set to 14.15V with temperature compensation off, to make sure it doesn't screw up. However, recently, I had been messing around with voltage to test outputs, and then put them back to normal 14.15V, and I afterwards I noticed it charging at 14.20V, and there was no way to fix it. So, I created another network and deleted the old one. That worked, but I have no idea how this 14.20 constant got left in the network.

It would be helpful if there was a page in the VE network configuration, which explained which MPPT was the "master", and which parameters it was going to use.

MPPT Controllers
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klim8skeptic avatar image klim8skeptic ♦ commented ·

@Astrayan do you have a reference source, BMV or SBS?

Any clues in the VE smart networking manual?

Temp compensation?

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astrayan answered ·

I've ascertained that if you have a few MPPTs, the VE bluetooth networking may use the lowest battery voltage to determine the real voltage of the battery. MPPTs often have a serious voltage drop to the battery when charging at high current, so are clueless about what the battery voltage is. Sometimes I wish there was a current compensation setting/calibration that negated all the voltage drop, but I dont know how it would be displayed. It would be even more confusing than temperature compensation.

This lowest voltage network quirk could be exploited by installing a low cost bluetooth MPPT with no significant solar current going to it. It would thus know the real battery voltage, and supply it to the network. But Victron probably has some other product that's a bit cheaper to do this.

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snoobler avatar image snoobler commented ·

Smart Battery Sense for voltage and temperature $40 Amazon.

Smartshunt for voltage, current and temperature if you get the probe $160 Amazon.

Add them to the VE.Smart network, and you get better data.

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astrayan answered ·

Thanks. Will look into the first one. Looks like a nice toy

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