Anyone else finding cheap AliExpress BMS units are actually decent these days?

Picked up a 4S 100A BMS for my 280Ah LiFePO4 pack last month — came in at just under £12 delivered. Was fully expecting it to be rubbish, maybe last a few weeks before thermal runaway or just dying quietly. But three weeks in, balancing looks solid on the cell monitor and it's handled a couple of proper high-draw moments (angle grinder off the inverter, roughly 1800W for a few minutes) without so much as getting warm.

The one I got is branded "Daly" — 4S 12V 100A, with the separate balance lead connector. Set the over-voltage cutoff to 3.65V per cell and under-voltage to 2.8V using the PC software, which actually worked first time, which surprised me. Bluetooth dongle was another £4 and the Android app is rough but functional. Total spend on BMS and monitoring is about £16, versus £60–80 for a JBD or £120+ for a Victron-compatible unit.

Has anyone else been running budget BMS gear for a decent stretch? Curious whether the Daly holds up over a full season or whether I'm just in the honeymoon period. Also wondering if anyone's done a proper comparison between Daly and JBD at similar price points — seems like those two come up constantly but I've not seen a solid head-to-head from anyone actually using both.

@AndreaHamilton the £12 price point is where I'd get nervous tbh. Had a cheap AliExpress BMS on my first DIY pack — worked fine for about 4 months then just stopped balancing silently. No drama, no failure, just quietly let my cells drift apart. Didn't notice until cell 3 was sitting at 3.1V while the others were at 3.4V.

These days I won't go below Daly or JBD/Overkill territory — still cheap enough but actually have community-tested firmware and proper Bluetooth monitoring. Fogstar sell pre-matched cells and recommend similar.

The real question with any budget BMS isn't whether it works — most do initially — it's whether the protection thresholds actually trigger when needed. Do you have a way to verify your overvoltage cutoff is actually firing at spec?

@AndreaHamilton £12 BMS protecting £200+ worth of Fogstar cells is like fitting a £3 padlock on a vault — technically a lock, yes.

@CharlieCampbell66 that padlock analogy is pretty spot on tbh

Running a Daly 100A on my garden office setup — paid around £28 from their official store. Not the flashiest but it's been rock solid for 18 months, temps fine, balancing works. Wouldn't go cheaper than that personally.

The £12 bracket worries me less about it dying and more about the protection thresholds being dodgy — overvoltage cutoffs that are slightly off can silently stress your cells over months before anything obvious happens.

If budget's tight, JBD/Overkill are the sweet spot imo. Proper comms, Bluetooth monitoring, and you can actually verify it's doing what it claims via the app. Worth the extra tenner.

@CharlieCampbell66 that analogy only holds if the cheap BMS is actually inferior though — that's the question being asked.

I've been running a no-name 8S 150A unit from Ali on my van build for about 14 months now alongside a Victron SmartShunt, and it's been solid. Balancing is a bit sluggish compared to my mate's Daly but cell voltages stay tight enough.

The real issue is consistency — you might get five good ones then one dud. No way to know before it fails.

What I do now is grab two units, test both under load before committing to either, return the dodgy one. At £12 each that's still cheaper than a single Daly and you've got a spare.

For EV charging loads though I'd be more cautious — spike currents are less forgiving.