False Low Battery war

We run ESS with 2x3 Array of MP2-5k. The L1 Master shows a red LED blinking for low battery alarm. System works without problems. Other 5 MP2 have no alarm. I wonder how the threshold can be diffrent for only one busbar ?

Pylontech BMS reports 49,15 Volt and 60% SOC and VEBus is in sync with BMS. My 3,5 digit voltmeter shows 49,2 or 49,1 Volt at the busbar and the DC connectors of MP2. No reasonable drop over the 200 Amp fuse. No notifications in the Cerbo GX.

DC Current meassured with 35 Amp equal at L1 Master and L1 Slave.

2 |3000

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Alexandra ♦ commented · Aug 14, 2023 at 11:33 AM

@Janvi

Sone clarification on the one busbar comment. .... Are they on separate bus bars?

It should be one central bus bar for all the inverters.

Have you tried swapping it to a different position?

Are you sure all the programming is the same for battery voltages?

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janvi Alexandra ♦ commented · Aug 15, 2023 at 04:26 AM

... only one busbar. As far as I see, I have to shut down the system and disconnect Cerbo to connect external MK3 cable for checking the thresholds. Its not possible to do this from Cerbo GX nor from VRM.

Much later at a SOC near to 10% the low battery is reported in notifications and inverters shut down like expected.

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