Hello! First the system facts:
2x12V 330Ah Smart LiFePO4 (in parallel) hooked up to (the negative system bus bar ) and a
Smart BMS’ 12-200 System+ port, which is connected to a positive busbar that unites the following:
2x Smart Solar MPPT 100/30 (each separately connected to a 550Wp solar panel),
1x Blue Solar MPPT 100/20 (+ smart bluetooth dongle, with a 2x 140Wp solar array in parallel connection),
1x Victron Phoenix 12/1200VA Inverter,
1x ECTIVE CSI 20 Inverter (2000W)
and the whole positive side of the boats 12V DC system.
After installing the mentioned setup (and running it without any trouble) for months, I ran into repeatedly high voltage readings on the BMS’ System+ Port towards the end of the charge cycle and reaching up to 16V. The battery voltage does never exceed 14,1V. It’s just the bus bar under elevated voltage.
These symptoms came after implementing a second inverter (ECTIVE CSI 20) and beginning to draw higher currents from the batteries while running the watermaker, e-hob or e-oven.
My first response was to check and adjust the advanced settings of the MPPTs in terms of “absorption duration” (changed from fixed: 2h to “adaptive” and “max. duration 1h”). This seemed the right remedy and the system would run for days and days without the over-voltage recurring before it started to behave in the same way again.
My next action was to adjust the absorption voltage from 14,2V to 14,1V and it helped again to prevent high voltage from happening.
Now again, daily, during the last charging phase, I have to manually turn of the MPPTs to prevent it. Either of the three MPPTs will push the system+ voltage way too high if left turned on.
If anyone could help or advise what to do/check on next, I would very much appreciate it.
Thanks, Mat