Hi everyone!
I've got a 16S 48V LiFePo4 system with a Smart Solar MPPT 150/85 MC4. ~80V OCV with 4 ~300W panels.
Been having issues with the MPPT charging intermittently. I switched BMS a few times thinking that was the issue.
Now the MPPT is not charging more than 0-10W/0-0.1A while in Bulk. I've connected the MPPT directly to the battery pack (without BMS) for troubleshooting to eliminate any other issues.
The MPPT charges perfectly when:
- connected to another 12V battery
- connected to any 4 connected cells of the 16S LiFePo4 assembly (set to 12V)
- connected to any 8 connected cells of the 16S LiFePo4 assembly (set to 24V)
(only charging for very short time and same time to avoid imbalance ofc)
As soon as I connect it to all cells at 48V it stops working.
I've checked battery continuity, individual cell voltages, cell connector bars. PV strip continuty is perfect, been charging a Bluetti unit at 750W without issues.
I've scoured this forum and tried everything remotely applicable.
The MPPT is configured with standard LiFePo4 settings. Charger is on, jumper connected and ofc it charges at <48V.
Is it possible that only the MPPT 48V charging circuit broke? Am I missing something?
Thanks!
