Victron BMS-712 Shunt Shut-off

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trinle asked May 24, '19

Victron BMS-712 Shunt Shut-off

We have a BMS-712 with 2x100 Ah Relion Lithium batteries and a Renogy solar setup (3x160w panels and a 40amp Renogy Rover Charger Controller.

Also have a 3000w Power TechOn PS1006 installed.

The issue us when I put a load on the system using the Inverter; say a 1300w toaster oven, the whole system will shut down and kill the Inverter within 15 seconds?

The reason for posting on this forum is that when that happens, I hear a click sound coming from the box where I installed the Victron Shunt?

Seems the shunt is shutting off the current under heavy loads. Is that even possible?

The whole system works fine under light or medium loads.

I measured the voltage of each 12v battery under this condition and the voltage is rock solid. At first I thought there was an over voltage on the batteries causing them to shut down for a few moments but this was debunked.

Victron settings for Li Relion batteries.

Battery Capacity 200Ah

Charged voltage 14.0v

Tail Current 2.00%

Peukert Exp: 1.10

Charge Efficiency Factor 99%

Current Threshold: 0.10A

Everything else is Defaults....

Any suggestions????

Also is there a tech support number in the USA to call for Victron Engery?

Thank You for your input.

BMV Battery Monitor Lithium Battery

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cardreader commented · Oct 04, 2019 at 05:43 AM

I had a very similar if not the same problem . Solved by upgrading inverter leads to 50mm cubed (?thick as little finger) cable and had no problem since .Worth a try.

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Answer 1 · 2019-05-24T07:27:09Z

Paul B answered · May 24, 2019 at 07:27 AM

The Victron shunt has NO switch of any kind in it, so it cant be the shunt

The only way it could be would be the shunt joins have a faulty weld but I have never seen that

If I were you I would do some more testing

ie

ByPass the shunt and see in you get the same issue under the same load. The shut down issue will be something else.

so Remove the shunt Join the two big wires and test some more.

I.e. Try measuring battery voltage at the connection to the inverter under load.

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Answer 2 · 2019-08-22T08:38:45Z

chrisryan43 answered · Aug 22, 2019 at 08:38 AM

I have just started having a very similar issue. Every so often i will lose all power from my LiFePO4 battery. It tends to be when a new load is added but it is very intermittent and not always a large load. I knew the problem was something close to the battery because the BMV-712 would lose it's SOC meaning it must have lost power. So either it was the battery shutting itself down or the BMV-712. The BMV-712 has been over reporting voltage recently (around 500mV - even though a multimeter at the shunt proved the correct voltage) and i thought it seemed a bit warm the other day so i was starting to suspect the shunt.

The next step is to bypass the shunt to be 100% sure. What was the outcome with your issue?

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kai ♦ commented · Aug 22, 2019 at 10:52 AM

Can you confirm that the shunt connection is all good? e.g. no issues with crimping from cables to lugs, lug contact area clean (no oxidation), lug is adequately torqued down.

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Answer 3 · 2019-08-22T10:37:20Z

Stephen Otto answered · Aug 22, 2019 at 10:37 AM

I’m guessing that the sudden load causes the voltage to dip low enough that the inverter is triggered to shut down to prevent over-discharge. Pretty common issue. Check your inverter settings.

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Answer 4 · 2019-08-22T12:10:54Z

ianddindustries answered · Aug 22, 2019 at 12:10 PM

Hi

I had an issue very similar to this and it turned out to be a loose terminal inside the battery between the cells. The problem was intermittent and only discovered by watching each cell voltage when it was faulting. As soon as the terminal was tightened it solved the issue

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wobby commented · May 29, 2022 at 03:04 PM

I’m having a similar problem with my lithium battery. How were you able to check the connections inside the battery. Mine has built in management for over, under and low temp.

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