question

Kaplan78 avatar image

Why is Victron battery monitor stuck at 100%

Hello, I cannot figure out why my Victron battery monitor is stuck at 100%. I have disconnected the load lead from the shunt and did a zero calibration with no luck either. I don't have any solar just a battery and DC output right now. Any ideas what is wrong? The charge has dropped all the way down to 11V with no change from 100%. Thanks


Equipment:

Battle Born 100AH Lithium battery

BMV-712 battery monitor connected to GX monitor

Charger/Inverter - Multiplus 2000watt


monitoringbattery system voltage
capture2.jpg (58.5 KiB)
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3 Answers
Justin Cook - Bay Marine Supply USA avatar image
Justin Cook - Bay Marine Supply USA answered ·

@Kaplan78, there are a couple immediate things to check, although they would require something being connected in a manner other than as shown on your schematic:

1: Check to make sure that the shunt is connected in the proper orientation; that is, that the battery is indeed connected to the "battery" side of the shunt rather than the shunt being reversed;

2: Check to make sure that all of your loads are indeed connected to the "load" side of the shunt and that none are bypassing it... your schematic looks perfect, but make sure it's really connected that way;

3: Check to make sure that your total battery capacity is properly set in the BMV-712; that is, if you have the one 100Ah Battle Born battery, make sure the capacity is set to 100Ah in the BMV, and also that charge efficiency has been changed to 99% and that you've set the Peukert exponent to 1.05%

4: It's worth noting that the BMV calculates SOC by current measured, not by battery voltage, so the fact that you're showing 100% SOC while your voltage has dropped down to 11v just tells me that current is being drawn from somewhere that is not being measured by the shunt (ie, a load is bypassing the shunt) OR that the shunt is connected in reverse (which would make the BMV think that a load is actually a charge)

5: As an entirely separate and (mostly) unrelated matter, that 100mA fuse at the shunt power supply needs to be replaced with a 1A fuse at your earliest convenience. It is a relatively recently discovered known issue that the 100mA fuse originally shipped with these can result in a number of problems later down the line. It's not responsible for this problem, but it'll cause you problems in the future.

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Went through all this meticulous planning to make sure everything was just right, and I flipped the shunt the wrong way. Always the simple things. Thanks so much Justin! Also the tip on the fuse I’m sure save me some future pain so thanks for that as well!

Hahaha no worries, we've all been there!

Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

Can you make some pictures of your wiring?

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Added diagram thanks!

If everything is 100% wired like in your schematic it should work.

Do you see any chrage/discharge currents at the BMV? If not maybe the BMV is faulty and you should get in contact with your dealer.

neoneddy avatar image
neoneddy answered ·

The load is not going through the shunt.

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Understand, I said it that way because the instructions say to disconnect the "load side" of the shunt. Thanks