Anyone else running a used EV battery for off-grid storage? Sharing my costs and setup so far

I picked up a second-hand Nissan Leaf 24kWh battery pack for £280 from a salvage yard in the Midlands back in March. The cells were at around 78% state of health according to the seller, so realistically I'm working with maybe 18–19kWh of usable capacity. For a static off-grid setup powering a small workshop and a converted outbuilding, that's actually plenty. Total system so far including a Victron SmartShunt and some secondhand 6mm² cable has come to just under £500.

The trickiest bit has been the BMS situation. The Leaf pack has its own internal BMS but it's not exactly chatty with third-party inverters. I ended up using a Batrium WatchMon to bridge the communication gap, which added another £180 to the budget. Not ideal, but I wanted proper cell-level monitoring rather than flying blind. Paired it with a secondhand Victron Multiplus 24/3000 I got off eBay for £220.

Charging is via 600W of used panels (two 300W mono panels, £60 each from a local Facebook Marketplace seller) and a Victron SmartSolar 100/30 MPPT. On a decent day in summer I'm seeing 2.5–3kWh into the bank, which is comfortably covering what I need.

Has anyone else gone down the salvage EV battery route on a tight budget? Particularly curious whether anyone's managed to get proper CAN bus comms working between a Leaf pack and a Victron system without spending a fortune on the interface hardware.

Wendy1967 | 847 posts

@DontPanic8 Brilliant find at that price! I've been running a similar setup with a salvaged Renault Zoe battery since last autumn - paid £340 for mine through a dismantler in Yorkshire.

One thing worth mentioning that catches people out: make sure you've got proper cell-level BMS monitoring rather than just relying on the pack's original BMS. The Leaf pack in particular can have cells that drift quite significantly once you start pushing it for stationary storage rather than the gentler EV discharge profile it was designed for.

Also worth budgeting for a decent contactor and pre-charge circuit if you haven't already - the inrush current when connecting to an inverter gave me a nasty surprise early on! Cost me about £45 to sort properly but saved the battery connections from taking a hammering.

What inverter are you pairing it with?

KeithWebb | 1,203 posts

@DontPanic8 Great score for £280! Worth mentioning that the 24kWh Leaf packs respond really well to a Batrium or Electrodacus BMS if you haven't sorted that side yet - don't skimp there, it'll protect your investment massively.

One thing I'd watch with the salvage yard SOH figures - they're often measured under optimistic conditions. Run a proper capacity test yourself before committing to your system sizing. I'd budget for roughly 70% usable in real-world conditions to be safe.

What inverter are you pairing it with? The Leaf modules sit around 7.6V nominal per pair, so your overall pack voltage will determine your options there. Plenty of people running them successfully with a Victron MultiPlus but the wiring takes some planning.

Ian1968 | 412 posts

@DontPanic8 Nice one! That's a cracking price for a 24kWh pack. One thing I'd flag that nobody's mentioned yet - make sure you've got proper thermal management sorted before the warmer months hit. These Leaf packs are notoriously passive-cooled from the factory, which is fine in a vehicle but can cause grief in an enclosed space like a shed or outhouse during summer. I keep a small fan running on a thermostat in mine just to be safe.

Also worth keeping an eye on individual module voltages rather than just overall pack voltage - a weak module can hide quite easily in the total readings but will drag your usable capacity down significantly over time. A proper BMS that monitors per-module is worth every penny at this scale.

What inverter are you pairing it with?