Hello everyone,
I recently bought a used Multiplus 12/1200/50 and connected it to a 300 Ah LiFePO4 battery (Renogy).
Unfortunately, the Multi isn’t working quite right, and I’m not entirely sure why.
The Multi is plugged into a wall socket at home. It’s not connected to a generator or anything like that.
Symptoms:
The AC input disconnects very frequently and then reconnects after a while, either at the end or just before the end of the bulk charging phase.
The DC charging voltage sometimes spikes briefly to 16V, sometimes even 18V at the end of Bulk charging. (Video 2:30 Mins) When it does that it completes Bulk, jumps to Absorption and seems to work ok until the next restart?!
It exhibits the same behavior even with the AC input set to weak (it disconnects, but less frequently).
Video of the behavior (sorry its in german): https://youtu.be/F6FwJarbCRE
The Multi is programmed correctly for LiFePO4 (14.2V/13.8V, Li-mode active).
The latest firmware, v557, is installed.
Does anyone have any ideas?