I have a 5K Sunsynk and Greenrich U-P5000 battery as a UPS setup.

Sometimes, rarely and inconsistently (Maybe once in 3 months or longer) I will hear a few beeps coming from the setup which stops and when I reach it I see the battery "restarting". Restarting being the lights acting the same as if I just switched on the battery. I do not know if the beeping comes from the inverter or battery.

This happens only once at that specific moment and not again until some months later.

There are no indications of errors on the Sunsynk screen. The SOH is 100%. I do not have montitoring software connected to it or even the Sunsynk dongle. The Greenrich manual does not seem to indicate anything. The setup is located in a well ventilated area and a few nights back it happened during cool weather.

The setup runs smooth during loadshedding and power cuts and charges normally.

I have had this setup for 2 years now. I cannot remember exactly when this started but I have a fading recollection of it being about a year back.

Electricty in our area is not always the smoothest.

Does anybody have an idea what the cause may be?

Edited March 17, 20251 yr by TheMac

[bump]

Does anyone have an idea?

[ping @Bruce Gu ]

If you are still struggling with this, I would strongly suggest putting some monitoring on the battery, and ideally the inverter as well. It doesn't have to be expensive or complicated. The Greenrich battery can be monitored with the Pace BMS software, using an RS232 to RJ9 cable. The Sunsynk inverter can also be monitored with an RS232 DE9 cable, which is connected to the dongle port (since you are not using the Sunsynk dongle), and monitored using any modbus software.

I use HomeAssistant to store/aggregate/present the statistics, and KellerZA/Sunsynk integration to collect data from the Sunsynk, and TertiusH/PaceBMS to collect data from the Greenrich.

On 2025/03/17 at 12:03 PM, TheMac said:

I have a 5K Sunsynk and Greenrich U-P5000 battery as a UPS setup.

Sometimes, rarely and inconsistently (Maybe once in 3 months or longer) I will hear a few beeps coming from the setup which stops and when I reach it I see the battery "restarting". Restarting being the lights acting the same as if I just switched on the battery. I do not know if the beeping comes from the inverter or battery.

This happens only once at that specific moment and not again until some months later.

There are no indications of errors on the Sunsynk screen. The SOH is 100%. I do not have montitoring software connected to it or even the Sunsynk dongle. The Greenrich manual does not seem to indicate anything. The setup is located in a well ventilated area and a few nights back it happened during cool weather.

The setup runs smooth during loadshedding and power cuts and charges normally.

I have had this setup for 2 years now. I cannot remember exactly when this started but I have a fading recollection of it being about a year back.

Electricty in our area is not always the smoothest.

Does anybody have an idea what the cause may be?

What time of day does this happen? Any time? When the sun is down?

I'm thinking that maybe there is a load that's demand is within the capabilities of the inverter but is too much for the battery and so the BMS shuts down.

1 hour ago, Bobster. said:

What time of day does this happen? Any time? When the sun is down?

It did not favour a specific time. Night or day.

(I don't have panels on. It is just a UPS)

Just the other day it happened during the day and I was close to it and tried to see something on the Sunsynk. I saw the following (not my photo) for a few seconds only while the battery seemed to be starting up.

So obviously the inverter cannot communicate with the battery during that time.

The biggest question would be whether the inverter is causing this "re-start" or is it the battery that is just restarting. As I was typing this I was wondering if I should consider replacing the comms cable between the battery and inverter.

Edited May 7, 20251 yr by TheMac