Anyone else had issues with deep-discharging an older LiFePO4 and then struggling to find out whether it's worth recovering vs. replacing?
Happened to me with one of my shepherd's hut batteries a while back — a 2019-era 200Ah unit. Left it over winter without a maintenance charge and came back to find it sitting at something embarrassing like 9V. The Victron BMS had done its job and disconnected, but by that point the damage was already done on a couple of cells.
Tried the slow-charge recovery method (trickle at 1A to coax it back above the BMS reconnect threshold), which did work, but capacity was noticeably down after cycling it a few times. Running it through a full charge/discharge test on the Victron battery monitor confirmed it was probably sitting at 60-70% of original capacity at best.
My questions for the collective wisdom here:
- At what point do you call time on a degraded LiFePO4 and just replace? Is there a capacity threshold you use as a rule of thumb?
- Has anyone had any joy getting older Victron Smart Lithium batteries looked at or warranty-claimed? Mine was well out of warranty but curious whether Victron UK distributors ever offer any goodwill on these.
- Would you replace like-for-like, or use it as an opportunity to switch to something like a Fogstar Drift which seems to be getting decent reviews lately?
The cost of a new 200Ah LiFePO4 has dropped so much since 2019 that replacement is probably the sensible call — but it still stings to write off a battery that technically still works.