Inverter beeps and dies at 03H00

[CathyV]

Hi all. Our inverter works fine during the day, but at 3 am every single night it bugs out, beeps for about an hour and then dies. This happens when we have power, but the unit shows the batteries depleting to 0 before it shuts off. During the day it charges just fine. 

If we turn it back on right away, the issue persists, but if we wait till we wake up in the morning (6am) it turns back on and works just fine. 

This means that everything wired to run off the inverter during load shedding, are not powered from about 4 - 6 every morning, which is really not ideal at all, as it's mainly the home security. 

The issue has been persisting for about 2 week now, regardless of load shedding schedule. 

[Arandoza]

It could be a few things?

1.) Check settings on the inverter? related to depth of discharge before returning to grid?

2.) Depending on the battery technology it could be a battery failed or BMS or BMS Failed or BMS Battery too Low issue. 

3.) It could be the incoming grid voltage is too high +240v, usually UPS's have a tolerance issue like this,  and so the inverter won't switch back to grid?  Probably a good idea to check wha the incoming voltage is? Could also be frequency related? In the early hours of the morning the grid has a low load and so the grid voltages tend to climb?

4.) Once the battery is depleted to 0%, it may need slow charging to get the battery back online, and once the sun comes up it starts charging slowly? from solar, whereas if you turn it all off and power back on it maybe tries to charge from grid, and doesnt like the state of the battery and so shutsdown again? or the BMS turns off the battery due to it being depleted? and too high a charge rate, when in low battery state. From what i have read, LIfePO4 batterys need to be trickle charged once they get down below 10 or 5% depending on the make, specs etc. to revive them.

 

What make and model inverter and battery banks, and if you have the settings maybe add them to your post. Maybe it will inspire some other suggestions.