Emergency shutdown battery plus and minus together or just disconnect the plus

DIY
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1

Hello,

MultiPlus, Quattro, SmartSolar MPPT
Emergency shutdown battery plus and minus together or just disconnect the plus.
I’ve heard that if the minus is disconnected it can cause damage? Is that correct?
(This is an emergency when the BMS has to disconnect the battery because of a technical defect.)

Kind regards

2

It is preferred to leave negative unbroken, but not mandated.
It matters more in three phase.

See the wiring unlimited just above here.

Is your bms breaking both negative and positve? Interesting, most only break one side when using a contactor. Or do you have another method you are trying to implement?

3

I will use an “ABB sace tmax” on the 48V battery side. This is controlled with a small relay current for triggering. Now the question is whether I should only separate plus or plus and minus at the same time? Which solution would be better for Multiplus, Quattro.
It is a very powerful off-grid system that has no connection to the public power grid. Due to a lack of alternatives, “Batrium” is used as a BMS because Victron does not offer a professional BMS.

4

Outside the battery disconnect only the plus side.
As on DC side are only 2 wires, one is enough to interrupt the current flow in the closed loop.
Usually the BMS is disconnecting the minus, inside the battery.