question

jonathan-drewes avatar image
jonathan-drewes asked

Erroneous Low Battery Alarm

This may be a tough one...

I had this erroneous Battery Low Voltage Alarm the other day.

The datalog file is attached.

The Multiplus2 gave this alarm which caused it to switch from inverter/battery source to grid the other day. When this happened, I measured the voltage at the battery, inverter input terminals etc, and they were all fine. The Multiplus and every other reading in the VRM and through VE.Congif were showing the correct voltages.

So, what caused this alarm?

The smart shunt in the system did not have a SOC at that time due to it being disconnected from power the day before and the battery was not yet at full charge. I say this because I have the Multiplus set to switch from battery to grid if the SOC < 15% and reconnect >35%, which had been working fine. When this alarm happened, the battery SOC was something like 70% or so.

Anyone have a clue here? A problem with the (new) Multi is all that I can deduce.

Any help is certainly appreciated.

The battery to Multiplus connections are very good, so that's not it.

See the highlighted rows for the alarm starting and ending. I was trying to get the alarm cleared by doing various things in between these times. Also, I'm not sure why the alarm cleared itself.

JDoffgrid_20221203-0950_to_20221203-1249.zip

Multiplus-II
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2 Answers
kevgermany avatar image
kevgermany answered ·

Throwing out ideas:

What batteries?

There are settings in the multi for low battery alarm, low battery inverter disconnect/reconnect.

If you're on lead acid, the voltage will drop quite a lot under load and could be triggering the alarm etc. By the time you check, voltage recovers from charging/resting.

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jonathan-drewes avatar image
jonathan-drewes answered ·

Trophy Lifepo4.

I use those settings to switch from battery to grid at 15% SOC but this event happened well above that level but the system did not have a SOC reading due to the smart shunt having been unpowered recently.

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