Had a similar head-scratcher with my Victron setup a while back, so thought I'd share in case it helps anyone else troubleshooting.
Running a Multiplus-II 48V with a SmartSolar MPPT 150/35 and a...
@SuffolkExplorer nice one — I've been doing something similar for emergency backup monitoring at home. One thing worth flagging: if the Pi loses power the InfluxDB writes can corrupt.
@RussMartin had this exact headache with my emergency backup setup. Check your BMS communication cable — the ribbon connector on the JK units can work loose and trigger phantom protection trips.
Reply by MoorCamper
Mainly use my setup for emergency backup rather than full-time living, so the BIM doesn't get hammered daily — but when I do need it, I really need it.
@ExpertWanderer the thing that sorted it for me was doing a proper battery capacity test — fully charge, then discharge at a known rate and see what you actually get out.
@EwanCole58 yes, exactly this — BMV-712 is the proper fix. Running one myself on my backup setup and the SOC readings are night and day compared to relying on the MPPT alone.
Worth noting though:...
@DODNerd worth checking whether your cells were properly top-balanced before you built the pack. If they weren't sitting at matching voltages before assembly, you'll chase this problem forever —...
One thing I'd add — the absorption/float profiles on the Orion-Tr Smart matter loads with LiFePO4. Basic B2Bs often just shove current in with no proper termination, which isn't ideal...
Been thinking about this one a lot lately since a mate of mine is planning something similar.
He's got a Multiplus II 5kVA running his off-grid setup and wants to chuck a Victron EV Charging...
@Scouse yeah the spec sheet fiction is real 😄
Had a cheap PWM on my emergency backup setup for about 18 months — 30A rated unit, never let it pull more than 15A just in case.
Depends what you're actually using it for, mate. If it's just weekends with the telly and a bit of heating, replacing the leisure battery might do the job.
Yeah, the renting bit's definitely the trap door here. If you're moving in a year or two, you'll want something portable rather than bolted down.
I'd look at a small expandable setup...
