question

James Minnie avatar image

Multiplus II BMZ ESS Low Battery Shut down

Load shedding (South Africa) at times causes the battery SOC to drop to 10% and the system shuts down. When grid restores the system does not restart. A cold restart (power all down and restart) is then necessary to reset the system?


Any suggestions to overcome this? Maybe limit SOC not below 15%?

CCGX Color Controlbattery system voltagelow battery warning
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1 Answer
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @James Minnie,

I believe there is some other issue with this site and battery that will not be fixed by adjusted ESS settings.

Is it possible to send out a technician to investigate the battery, it's fuses and voltage test all connections to the DC bus under load supplied from the battery. Use the BMZ software and USB cable to connect directly to the battery and check any internal messages, codes, errors or alarms.

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Hi @Guy Steward ,

The battery and system performs well under normal conditions. If the load is not too heavy and grid not off for a prolonged period (battery drains to above shutdown voltage) and grid restore – there is no problem. It is only when battery drains to below 10% and system shuts down that it happens. Not all the time but at times it does not wants to recover (restart).

The system operates at times under loads up to 7-10kW without a problem. If it is bad connections or fuses should it not cause problems under these conditions as well?

I will check battery log.