Anyone else gone down the used forklift battery rabbit hole for cheap LiFePO4 storage?

Been reading loads about folk in the US doing this but wondering if it's actually practical over here. The idea being you pick up a used 48V forklift or pallet truck battery — often lithium iron phosphate cells inside — for a few hundred quid off eBay or a local industrial auction, test the cells, and end up with a decent chunk of usable capacity for pennies per kWh compared to buying a brand new BYD or Pylontech setup.

I found a 48V 300Ah unit on Facebook Marketplace last week, a retired BT-branded pallet truck battery, listed at £350. Seller reckoned it had done about 60% of its rated cycles. I didn't pull the trigger because I genuinely don't know how to assess whether the cells inside are worth the hassle — or even which chemistry they actually are, because apparently not all forklift lithium packs are LiFePO4.

Has anyone here actually bought one, cracked it open, and done a proper capacity test? I've got a basic RC battery charger (iCharger 4010 Duo) that I use for smaller packs, but obviously that's not going to cut it for something this size. I'd need a proper discharge load setup and presumably a BMS swap or at least a BMS check before connecting anything to my inverter.

Would love to know what gear people are using to evaluate these things before committing, and whether the saving is genuinely worth it versus just buying refurbished Grade B prismatic cells from one of the Chinese suppliers.

@FellFrank done exactly this for my shepherd's hut build. Picked up a 48V 200Ah pallet truck pack off eBay for £180 — bloke was replacing a fleet. Cells tested fine, just needed a proper BMS swap.

The catch nobody mentions: balancing. These packs have often sat unbalanced for months. Worth budgeting for a decent active balancer before you trust them under load.

Also finding a BMS that actually fits the cell count is faff. Ended up going Daly which isn't glamorous but does the job.

Paired mine with a Victron SmartSolar and it's been solid all summer. Total system probably £400 all in vs £800+ for equivalent new Fogstar capacity.

Main UK-specific tip — search "traction battery" on eBay rather than forklift, throws up more results.

@MikeCross that £180 figure made me do a double-take — genuinely impressive. Worth flagging though, the BMS situation is where it gets complicated on these packs. Some forklift cells come with proprietary comms protocols that won't talk nicely to a Victron SmartShunt or Cerbo without a fair bit of fiddling or bypassing entirely.

My shepherd's hut runs on properly spec'd Fogstar cells so I haven't gone this route myself, but I came very close last winter. The thing that held me back was the uncertainty around cycle count history — there's no equivalent of a car's MOT history for battery packs, and some of these have done serious graft on warehouse floors.

Anyone found a reliable way of load-testing these before committing? That feels like the missing piece before this becomes a proper recommendation for budget builds.

Really interesting thread this. @MikeCross that price is remarkable even accounting for cells needing assessment. One thing worth adding for anyone going down this route — sourcing a compatible charger profile matters enormously with these packs. Many of the cheaper 48V chargers floating around assume lead-acid chemistry and will either undercharge or stress the cells. Worth either reprogramming a decent CC/CV charger or budgeting for a proper LiFePO4-specific unit from the off. Also, if anyone's near industrial estates or logistics hubs, it's worth knocking on doors directly rather than waiting for eBay listings — I've heard of people picking up batteries free or nearly free from places just wanting shot of them before a site clearance.

@GaryParker97 raises the BMS point which is the critical issue nobody seems to nail down properly. Most of these packs use proprietary CANbus-communicating BMS units — the forklift OEM locks everything to their ecosystem. You've got two realistic paths: retrofit a Daly or JK BMS after cell extraction (adding labour and component cost), or attempt CANbus decoding which is genuinely advanced territory.

For a garden office application like mine, I ended up budgeting the full rebuild cost before committing, not just the pack price. Cell testing with an capacity analyser, replacement busbars, new BMS, and enclosure fabrication. Still cheaper than new Fogstar cells, but the £180 headline figure can balloon considerably.

Worth checking whether the pack used prismatic cells or cylindricals — prismatic rebuilds are far more tractable for DIY work.