Multi RS 48/6000 overcharging - inverter only setting not doing anything

Hello! If anyone can shed any light I would be most grateful. I’ve been running a setup for nearly 3 years without issue, but suddenly my Multi RS inverter charger wont stop charging my batteries at the set point. of 47.9V
I’m running a multi RS solar, two 24v Tesla model S lithium battery modules in series for a 48v system, and a 48v Battery protect. I have 2 BMS’s that were made by 057 technology (who have now gone bust or out of business) The multi RS used to over run a little bit up to about 48V but now seemingly will just keep going, it got to 49V yesterday, and I’m having to cut the charging of manually via the breakers as the system seems to just not be doing it. Weirdly my BMS’s are also activating a relay which is suposed to be activating the remote connections on the BP and cutting feed to batteries at 48v. I left quite a large margin for safety which has served me well up until now.

I think the ‘chain’ connection between my two bms’s had gone faulty at some point which led to a 200+mv discrepancy between my battery modules which I have manually put right with a 24v load whilst the system was off, but this has not sorted out the over charging problem.

I also tried to switch my system to ‘inverter only’ today whilst it was charging off solar, and it just kept charging.

the only real thing that i’m aware of that has changed is that i’ve updated the multi rs software as the updates became available. although can’t say whether this has anything to do with it or not.

is anything jumping out at anybody as the cause?

this has got me stumped so will very much appreciate any pointers.

Many thanks.

Neil

Just to clarify, the bms’s triggering the relay that is supposed to trigger the BP, seems to not be working, not sure how or why, the relay is definitely activating but somehow charge still being allowed to get to batteries. but the multi rs should just stop charging despite this. so seems like more than one problem

little bump. - I think the battery protect may be responsible for the over voltage now, but it doesn’t explain the ‘inverter only’ setting doing absolutley nothing, Anyone experienced that at all?

I believe your system is too niche for similar experiences…
Do you have a Cerbo-like equipment? Is your BMS talking with it?
If not, and even then, did you set the proper voltages in the Multi RS battery section?
Did you verified that are not modified?
Did you tried a cold restart, meaning powering all off and then back on?
Is it possible that after 3 years the battery to show signs of aging?