Batteries not charging after adding new battery
I had a 4th battery installed on 14th Feb 2025. I have been running my Sunsynk 8Kw on 3x 5.32 Sunsynk wall mount batteries since June 2023. The new battery seems to prevent any of the other batteries from charging. If I switch off the 4th battery then
the other batteries charge.
BMS shows 300A with 3 batteries and does go up to 400A when the 4th battery is on. The BMS screen shows "Request Force Charge" in the bottom left part of the screen when battery 4 is on. Not sure how to make this request. 4th battery was installed as the last slave battery. I did suggest that it should be master because of newer firmware, but don't know for a fact that that will cause problems.
No arms LED's or log entries.
I also noticed my SOC spiking to 100%. It never did that before. I thought this was preventing charging, but it still spikes to 100% now , even when running on 3 batteries with Battery 4 powered down at the front switch.
4th Battery is 34% to 50% by LED SOC indication.
I have not done a full shut down and boot yet since the power up after the battery was installed.
Can the old and new firmware versions cause these problems or are there other checks I can do?
AFAIK the charge could be from solar if available. In my case the situation has arisen when the battery is discharging, so this would naturally occur when no solar is available