As of this morning, I have a strange issue with my Victron ESS system. My battery, despite being charged to 78% with a healthy voltage of 53.44V (16S 3.2V 280Ah LFP cells) according to the JK BMS, it’s just not being used - it stays in idle.
As a result, my solar is pushing generation back to the grid without charging the battery.
I’ve tried various settings to provoke, (turning off ESS, raisin the minimum charge level to 80%, setting ESS to “Keep batteries charged”), but it doesn’t charge, nor discharge.
And when my solar production drops and demand exceeds solar, it’s taken from the grid instead of the batteries.
I’ve checked via remote console and can’t see anything wrong. The BMS is allowing charging, discharging and balancing. So why isn’t it being used ?!
I was using Mr Manuel’s / Louis BMS manager and have reloaded that. I’ve also rebooted by Cerbo GX but once it syncs to the grid, the battery still doesn’t get used despite showing up and being in a nominal status.
looking at the history, what is interesting is that the battery was charging overnight in a scheduled charge.
At around 2am, more or less when it appears to have stopped charging, I have a sleuth of VE.Bus System [276] Low battery: Alarm in the logs - but that’s with the battery at over 53V and it’s been charging all this time.
A bit later, I have a Solar Charger - Solar Error code: #29 - Over-charge protection.
It then seems to variably switch between low voltage and over-charge protection. It’s almost as if the communication was corrupted or something - I’ve been using an RS485-USB dongle connected to the JK BMS and that’s always been flawless.
The last set of alarms are:
0 Solar Charger - Solar Error code: #29 - Over-charge protection 2025-03-13 10:33:39 25s
0 Solar Charger - Solar Error code: #29 - Over-charge protection 2025-03-13 10:33:05 25s
276 VE.Bus System [276] Low battery: Alarm 2025-03-13 10:32:43 1m, 32s
0 Solar Charger - Solar Error code: #29 - Over-charge protection 2025-03-13 10:32:37 25s
276 VE.Bus System [276] Low battery: Alarm 2025-03-13 10:30:05 1m, 42s
0 Solar Charger - Solar Error code: #29 - Over-charge protection 2025-03-13 10:30:00 25s
0 Solar Charger - Solar Error code: #29 - Over-charge protection 2025-03-13 10:29:12 45s
276 VE.Bus System [276] Low battery: Alarm 2025-03-13 10:02:07 21s
But now, everthing appears normal.
Could the system somehow refuse to use the battery because it’s decided it’s “unreliable”? I can’t see where that would be flagged. There are no current alarms and the BMS reports charging, discharging and balancing “on” in remote console.
Now if it was the other way around, that could make sense, even if not right. But having the MP2, i.e. the “remote connection” suggest the voltage is higher than at the source with the BMS ?!
Edit, I guess the MP2 is reporting a higher voltage as the MPPT is currently running
Having looked at the graphs, it’s clear a fuse or something has gone as the current dropped immediately during a charging session.
I’ll arrange to physically check over the next few days.
