SolarEdge Home Battery 48V – BMS not responding after 1 year storage (possible recovery?)

Has anyone actually managed to wake one of these up after deep sleep from prolonged storage? I've got a similar situation with a different chemistry (LiFePO4 cells in my shepherd's hut setup) where the BMS went completely unresponsive after sitting unused over winter.

What worked for me was a slow trickle charge directly to the cell terminals — bypassing the BMS entirely — just enough to bring the pack voltage up above the BMS's minimum wake threshold. Used a bench power supply set to around 0.1C. Took a few hours but the BMS eventually came back to life.

The SolarEdge Home Battery uses a 48V nominal architecture, so I'd be curious whether the same approach is viable there or whether their proprietary BMS logic makes that trickier. A few questions:

• Do you know the current pack voltage at the terminals?
• Has the BMS thrown any fault codes via the SolarEdge monitoring portal, or is it completely dark?
• How long was it in storage — and was it stored partially charged or at a very low state of charge?

The worst outcome with lithium storage is if cells have dropped below around 2.5V each — at that point some BMS units will permanently latch into protection mode and refuse to recover even with a proper charge applied.

Worth checking whether SolarEdge have a recovery procedure in their installer documentation. Fogstar and Victron both publish this sort of thing, but proprietary systems can be a nightmare. Might also be worth a call to your installer before poking around inside — warranty implications and all that.

@Bazza LiFePO4 in deep sleep is basically just the battery cosplaying as a paperweight. 🪨

Seriously though — if your BMS has gone full silent treatment, try a slow trickle charge directly to the cells (bypassing the BMS entirely) to nudge cell voltage above the wake threshold, usually around 2.5

@Bazza had exactly this with my van build — Fogstar cells sulking after sitting over winter like a teenager on a Sunday morning. Trick that worked for me: trickle in at 0.05C with a bench PSU, manually bypass the BMS just long enough to nudge cell voltage above the wake threshold, then reconnect and let it do its thing. Do NOT just hammer it with a charger expecting miracles — you'll confirm the BMS's suspicion that it's better off dead. Worth grabbing a cheap cell voltage tester first to confirm you're actually dealing with deep discharge rather than a genuinely deceased BMS, because those are two very different problems with very different credit card implications.

@Bazza had this exact drama with my cabin setup — grabbed a Victron SmartShunt and trickle-fed the cells back up from around 2.4V per cell using a bench PSU set to painfully low current, basically treating them like a nervous rescue cat 🐱

Key thing nobody mentions: check each cell individually before you blast the whole pack — one dud cell in there will just absorb everything and the BMS stays deaf regardless.

Took mine about 48 hours of coaxing before the BMS finally blinked back to life like it'd just remembered it had a job to do.

Done this twice on my narrowboat — once with a Fogstar pack that spent eight months in a bilge sulking harder than my ex.

Key thing nobody's mentioned: check your BMS supply voltage separately before assuming the cells are the problem. A dead BMS rail will fake a "no response" situation even when the cells themselves are fine. Measure directly across the cell terminals — if you're above 2.5V per cell on LiFePO4, there's almost certainly life in them.

Recovery method that worked for me:

• Bench PSU set just above resting voltage
• Current limit to 0.05C (go slower than you think)
• Let it sit 20–30 mins before the BMS wakes up enough to talk

@VoltMax's SmartShunt tip is spot on for monitoring the process. Patience is the actual tool here — rushing it is how you end up buying new cells. 🔋