Anyone else running a used EV battery for off-grid storage? Picked up a Nissan Leaf pack for £180 and slightly terrified

Last month I grabbed a 24kWh Nissan Leaf gen1 battery (2013 plate, around 75% SoH according to the seller's LeafSpy screenshot) off eBay for £180 including collection from a scrapper in Coventry. The plan is to use it as a house bank in my Transit conversion, fed by 400W of second-hand panels off Facebook Marketplace. Total panel spend so far: £65. Feeling pretty smug about the budget side of things.

The issue I'm now staring at is the BMS situation. The Leaf's onboard BMS doesn't communicate nicely with a standard solar charge controller — I've been reading about people using a Batrium or Electrodacus to sit in between, but those aren't exactly "on a budget." Someone on another thread mentioned hacking the CAN bus with a Raspberry Pi and some open-source code, which sounds brilliant until it all goes wrong at 2am in a layby in Wales.

Has anyone here actually got a salvage EV pack running reliably with a budget BMS solution — ideally under £100? Particularly interested in whether anyone's used a JK BMS wired to individual module groups rather than the whole pack. I've got 48 of the pouch cells to play with so in theory I could reconfigure, but I'm not sure I'm brave enough yet.

Kingy74 | 847 posts | ⚡ Solar & Storage Obsessive

@CamperAndrea brilliant score for £180! That's roughly 18kWh usable at 75% SoH which is cracking value.

Few things worth knowing from my own gen1 Leaf pack experience:

The cells themselves are pretty robust but the original BMS won't communicate nicely with most inverter-chargers, so you'll want a JK BMS or similar sitting between them and your system. Don't skip this - thermal management on these packs is genuinely poor and they will drift under load without proper cell monitoring.

Also worth doing an actual capacity test yourself rather than trusting LeafSpy screenshots from a seller - they can be... optimistic, shall we say.

What inverter are you planning to pair it with? That'll determine a lot of your wiring decisions. And have you got somewhere reasonably ventilated to house it? These do like a bit of airflow.

Gazza75 | 312 posts | 🔋 12v → 48v convert

@CamperAndrea cracking find! I've been running a 2014 Leaf pack for about 18 months now, similar vintage to yours. One thing nobody mentions early on - those gen1 packs have no internal heating or active cooling, so keep an eye on charging them in cold weather. I won't charge mine below about 5°C, just not worth the risk to the cells.

Also worth getting your own LeafSpy dongle (OBD2 Bluetooth adapter, about a tenner off Amazon) so you can monitor it yourself rather than relying on the seller's screenshot. Check the individual cell group voltages - you want them all sitting close together. Any outliers and you'll know which module needs attention.

What BMS are you planning to use with it?

BitsAndBobs | 1,203 posts | 🚐 Van/Office/Chaos

@CamperAndrea £180 for 18kWh usable is cheaper per kWh than my dignity after I told my wife how much I spent on Victron kit — absolute steal mate. Main thing nobody's mentioned yet: those gen1 Leaf packs have no active thermal management, so if your garden office/van/shed gets proper Baltic in winter or bakes in summer, your cycle life will suffer badly. Keep it between roughly 10°C–35°C if you can. Also grab a Fogstar-compatible BMS or a proper JK unit before you hook anything up — that pack will have the Leaf's OEM BMS but you'll want something you can actually monitor properly. Running mine through a Victron Multiplus and it talks beautifully once you've got comms sorted.

Taffy | 134 posts | ⛵ Boats & Backup

Running a smaller salvage pack on my boat so genuinely curious — what BMS are you planning to use with it? The Leaf modules are nominally 7.5V pairs aren't they, so you'd need something that can handle that cell grouping properly rather than treating them as straight LiFePO4.

Also worth asking: did the seller have any data on which specific modules are weakest? On a 2013 pack at 75% SoH the capacity will be quite uneven across modules. A decent active balancer might be worth budgeting for alongside whatever BMS you choose.

For the boat I went Victron for the monitoring side — overkill possibly, but the visibility into cell-level behaviour gave me real peace of mind on something that could genuinely sink if it goes wrong. What's your use case — static home storage?

OldSailor86 | 847 posts | ⚓ Boats, Vans & Emergencies

@CamperAndrea @Taffy — boat use is where I'd urge the most caution here. Spent two seasons running a salvage pack aboard and the humidity alone aged the cells noticeably. What eventually sorted me out was a Victron SmartShunt giving me proper coulomb counting rather than trusting the native BMS's SoC figures, which on an old Leaf pack can wander badly.

On the "slightly terrified" front — respect that instinct. Gen1 Leaf packs have no active thermal management, so if your install space gets warm in summer, those cells are already degraded and won't thank you for it.

The £180 price is genuinely excellent though. Just budget another £80–120 for a decent active balancer before you start hammering it.

What's the intended application — continuous daily cycling or occasional backup?

TransitConvert | 312 posts | 🏡 Garden Office

Running a garden office setup here so definitely watching this thread. My concern with a gen1 Leaf pack is the thermal management — or lack of it. Those cells aren't actively cooled, which is fine in a car where you're managing discharge rates carefully, but sitting in a shed through a British summer and winter with bulk charging cycles regularly hitting them feels like a different situation entirely.

@CamperAndrea did the LeafSpy screenshot show individual cell group voltages or just overall SoH? Wide cell variance on an old pack is arguably more important than headline capacity — you could have 75% average but one weak module dragging everything down and tripping your BMS at awkward moments.

What are you actually planning to use as your BMS? That feels like the critical decision here before anything else gets connected.

GlenKelly | 203 posts | 🏠 Off-grid Smallholding

@CamperAndrea that's a cracking price for a 24kWh pack, even derated. The gen1 Leaf modules are well documented and the community around them is solid. Worth joining the DIY Battery forum alongside here — masses of teardown info specific to those cells.

One thing I'd flag: at 75% SoH those LeafSpy readings can be optimistic. Budget mentally for maybe 16-17kWh usable once you've got a proper BMS managing the cell groups sensibly. Still brilliant value at £180 though — I paid more than that for a fraction of the capacity new!

GoldenMechanic | 156 posts | 🔧 Van, Garden Office & Emergency Backup

@CamperAndrea what BMS are you planning to use with it? That's the bit that keeps me up at night with these secondhand packs — the original Leaf BMS isn't really designed for stationary use and won't talk nicely to a Victron setup without some serious wrangling.

Has the seller given you any cell-level balance data from LeafSpy, or just the headline SoH figure? A pack sitting at 75% overall could still have one or two modules that are properly knackered dragging everything down.

£180 is genuinely impressive though. Annoyed I missed that listing.