105 Nissan Leaf Cells, Batrium BMS, ABB 300 amp breaker, big copper bus bars + kits to make 48v golf cart batteries with bms...

Has anyone actually used Leaf cells to build a 48v bank for EV charging purposes? I've been eyeing up setups like this for a while now and wondering whether the second-life Leaf cells are still worth pursuing given how the prices have shifted lately.

The Batrium BMS pairing is interesting — I've seen a few builds with it and it seems pretty solid for larger cell counts, but does anyone have experience balancing 105 cells without it becoming a nightmare? Presumably you'd be looking at a 16s arrangement for 48v nominal?

A few questions if anyone's gone down this route:

• What capacity are you actually seeing from used Leaf cells after degradation? I imagine there's a huge variance depending on the source
• Is the ABB 300A breaker adequate for DC-side protection at that voltage, or would you uprate it?
• Bus bar quality — are we talking proper machined copper or more DIY plate stock?

I'm running a Victron MultiPlus-II and eventually want to tie in a proper cell-based bank rather than relying on my Fogstar 48v units long-term. The Leaf cell route seems appealing from a cost-per-kWh standpoint but I'd want to know what the real-world gotchas are before committing.

Anyone here actually completed a build like this and can share honestly how it's performing a year or two in?

@Cleggy done something similar in my motorhome — not for EV charging but same cells principle. Second-life Leaf cells are decent if you're careful about matching them. Key thing is checking the capacity of each cell before you commit, they vary massively depending on which generation Leaf they came from and how hard they were used.

Batrium is solid for monitoring, worth every penny for the peace of mind on a big bank like that.

Main gotcha I'd flag — 105 cells sounds like a lot but check your actual usable capacity once you've factored in state of health. Some of those cells are already down to 60-70% SoH.

What's your intended charge rate? That'll affect whether the ABB 300A breaker is sized right for your setup.

@Cleggy worth flagging that Leaf cells are NMC chemistry, so your BMS needs to be properly configured for the correct voltage window (3.0–4.2v per cell, not LFP parameters). Batrium handles this fine but double-check whoever's selling these kits hasn't pre-configured it for LiFePO4.

For EV charging specifically, your limiting factor will likely be sustained discharge rate rather than capacity — worth calculating your peak draw against the cell's C-rating before committing.

My shepherd's hut runs LFP for exactly that reason — more abuse-tolerant when loads are unpredictable. Second-life NMC needs a bit more babysitting.

The ABB breaker is a solid choice though. No complaints there.

@CurrentAffairs makes a fair point on the chemistry side — caught me out early on with my own build.

One thing nobody's mentioned yet: cell matching is everything with second-life Leaf packs. You want to test internal resistance across all 105 before you even think about assembly. Cells from the same donor vehicle can still vary wildly depending on which module position they came from.

I used a Batrium WatchMon4 on my tiny house bank and the granular cell-level data it gives you is worth every penny — especially with mismatched second-life cells.

Also worth checking whether that ABB breaker is rated for DC at 48v specifically. AC ratings don't carry over. Learned that the hard way.

@CurrentAffairs is absolutely right on the NMC voltage window — 2.5V to 4.2V per cell — but worth adding that Leaf cells in particular (especially pre-2016 modules) suffer from no thermal management from factory, which becomes a serious concern when you're drawing the kind of sustained current EV charging demands.

With my narrowboat bank I run Victron kit throughout and the Batrium BMS in that listing is decent, but you'll want to verify the cell-level monitoring configuration carefully — Batrium's Longmon units need correct placement per Leaf module pair.

Also flag: second-life cells vary enormously in remaining capacity and internal resistance. Without proper initial impedance testing (a basic capacity cycle at minimum), you're essentially buying a lottery ticket. 105 cells sounds a lot until three modules are significantly degraded and your usable capacity drops sharply.

What's your target usable kWh and charge rate?

@Cleggy one thing worth considering beyond the chemistry discussion above — cell balance degradation across a second-life pack is highly variable depending on which generation Leaf the cells came from. Gen 1 cells (pre-2016, passive cooling) tend to have significantly worse capacity spread than gen 2 onwards. Before committing to a Batrium setup, I'd strongly recommend individually capacity-testing every cell with something like a Junsi iCharger before assembly. Batrium's cell-level monitoring is excellent once running, but it can't compensate for a pack built on unmatched cells from the outset. For an EV charging application specifically, you want tight capacity matching — the discharge rates will stress any weak cells disproportionately. Worth the extra few days upfront.