Anyone else running 100Ah LiFePO4 on a tight budget — what BMS are you actually using?

Finally took the plunge and built a small 12V leisure battery bank for my Transit camper. Went with two 50Ah LiFePO4 cells from a Chinese supplier on AliExpress — came to about £65 all in including shipping. Not bad, but now I'm stuck on the BMS and I don't want to cheap out on the one bit that actually protects the cells.

I've been looking at the Daly 100A 4S units which seem to be everywhere for around £15–£20. Reviews are all over the place though — some people swear by them, others have had them cut out under load or fail to balance properly after a few months. I'm only running a 40L compressor fridge (draws about 4–5A on average) and charging off a 200W roof panel through a Victron 75/15 MPPT, so nothing wild in terms of loads.

Has anyone actually run a Daly long-term on a similar setup, or is it worth stretching to something like the JBD/Overkill Solar boards for the Bluetooth monitoring alone? The extra tenner or so isn't a dealbreaker if it genuinely makes a difference. Just trying to keep the whole build under £200 if I can.

@BatteryDoug nice one on the budget build. I ran a similar setup in my motorhome for about 8 months before upgrading.

Was using a Daly BMS — the 100A version, picked it up for around £18 on Amazon. Does the job honestly. Basic protection, nothing fancy, but it's kept things safe.

Only thing I'd say is watch the low-temp cutoff — Daly's can be a bit aggressive in winter and you'll lose connection unexpectedly. Caught me out parked up in Scotland in February 😅

If budget allows slightly more, the JBD/Overkill BMS is worth the extra tenner — Bluetooth monitoring changes everything when you're troubleshooting.

What cells did you go with specifically? Some of those AliExpress listings are genuinely decent (EVE, CATL rejects) but others are... optimistic on the capacity claims.

Hey @BatteryDoug, solid build for the price! For budget LiFePO4 setups around that capacity I've had good results with the Daly 100A Smart BMS — picks up for around £18-22 on AliExpress and has Bluetooth monitoring built in which is genuinely useful for keeping an eye on cell balance. The app is a bit clunky but it does the job.

One thing worth checking — did your cells come pre-balanced? I'd stick them on a balance charger before wiring everything up if you haven't already, otherwise you might trigger low voltage cutoffs on the weaker cell prematurely and wonder what's going on.

Also worth grabbing a separate cell voltage tester for a few quid just to have on hand. Makes diagnostics much easier down the road. Good luck with the Transit build, love seeing budget setups done properly! 🔋

@BatteryDoug ran almost exactly the same setup in my van conversion — grabbed a JBD (also called Jiabaida) 4S BMS off AliExpress for about £12 and it's been rock solid for 18 months now. Does proper cell balancing, has Bluetooth on the pricier variants if you want to keep an eye on things.

Only gotcha — make sure you get the correct amp rating for your expected load. I cheaped out first time and popped a 20A unit running a compressor fridge 😅

If budget stretches slightly, the Daly Smart BMS is a step up and still won't break the bank. Loads of Transit builders on here swear by them.

Either way, don't skip a proper fuse between the battery and BMS — ask me how I know 🔥

@BatteryDoug curious what balancing current you're getting on that JBD — @George1975 mentions it but doesn't say which variant. There seem to be about 47 nearly identical listings and I've genuinely lost the will to live trying to differentiate them.

Running a Fogstar Drift 100Ah in my garden office so slightly different ballgame, but I went with the Daly smart BMS before eventually caving and buying a proper Victron SmartShunt just to actually trust my state of charge readings.

Two questions worth asking yourself with any budget BMS:

• What's the actual low-temperature cutoff? UK winters will catch you out
• Does it have proper overcurrent protection or just a polite suggestion of one?

Has anyone tried the JBD app over Bluetooth on Android recently? Last time I looked it felt like it was designed by someone who'd only heard of phones.

Really useful thread this — just to add a slightly different angle, I run a Daly BMS on my motorhome backup bank and it's been rock solid for about 18 months now. Got the 100A version for around £18 shipped.

One thing worth flagging for @BatteryDoug — whatever BMS you go with, double-check the low-temperature cutoff setting. UK winters catch people out, LiFePO4 really doesn't like charging below about 5°C and a decent BMS should protect against that automatically.

@George1975 raises a good point about JBD — the PC/Bluetooth app support is genuinely handy for monitoring. Daly has a similar app but it's a bit clunkier in my experience.

Has anyone tried the Fogstar Drift cells paired with a budget BMS rather than buying their ready-made packs? Wondering if the savings stack up properly once you factor in the BMS cost.