Anyone else had issues with a Daly BMS cutting out in cold weather?

Had this exact problem last winter with a 280Ah LiFePO4 pack in the static caravan. Daly 100A smart BMS kept tripping out overnight when temps dropped below about 4°C. Took me an embarrassingly long time to realise it was the low-temperature charge protection kicking in rather than an actual fault.

The Daly's default low-temp cutoff is set quite conservatively from the factory — think mine was triggering around 5°C charge temp which is frankly useless for anything in the UK between October and March.

A few things worth knowing:

• You can adjust the temp thresholds via the Daly app over Bluetooth, but the interface is genuinely awful
• Low-temp cutoff only affects charging, not discharge — so if your inverter is still running but the BMS won't accept charge from your panels/hookup, that's probably what's happening
• Some people fit a small self-regulating heat mat to the cells, wired to a thermostat. Bit of a bodge but it works

I eventually moved to a Daly with a proper heated battery option considered, then ended up just going Victron + Fogstar Drift cells with a decent insulated enclosure. Night and day difference in winter reliability.

Anyone else found a cleaner fix for this? Particularly interested whether anyone's managed to get the Daly parameters dialled in properly without wanting to throw the app out the window.

@WhatsAFuse65 — aye, been there. Van conversion, last February, parked up in a layby somewhere near Stirling. Woke up at 2am to a dead Fogstar 200Ah pack because the Daly had decided 3°C was unacceptable.

The culprit was the low-temperature charge protection tripping — even with no active charging happening, some BMSs get twitchy about discharge too once cells drop far enough.

What actually sorted it for me was a cheap self-regulating heat mat wrapped around the battery, wired to a simple thermostat controller. Kicks on at 5°C, off at 10°C. Pulls barely anything overnight.

Switched to Victron SmartShunt alongside it for proper monitoring — at least you can see what the cells are doing before it all goes dark.

Still running the Daly. Still don't entirely trust it.

Narrowboat winters sorted me out fast — slapped a Fogstar heat pad under the cells and now my Daly thinks it's permanently in Marbella.

@WhatsAFuse65 worth understanding why this happens — LiFePO4 cells have a genuine electrochemical limitation below ~0°C where lithium plating occurs during charging, so the Daly is actually doing its job correctly by triggering low-temperature charge protection. The cutout isn't a fault, it's a feature.

The real fix is a proper thermal strategy rather than fighting the BMS:

• Self-heating cells (EVE 280K variants have this built-in)
• Insulating the entire battery enclosure — even 50mm Celotex makes a dramatic difference
• @WonkyHermit's heat pad approach works brilliantly, but wire it to a thermostat controller so it only activates below ~5°C rather than running continuously

Also check your Daly's low-temp charge threshold in the PC software — some units ship with it set aggressively high (8–10°C) when 0°C is perfectly acceptable for quality cells.

@DailySolar raises the important point, but I'd push back slightly — the Daly's low-temp cutoff threshold is notoriously conservative and poorly calibrated on the cheaper units. Mine was tripping at 4°C ambient when the cells themselves were still sitting at 7°C. The NTC sensor placement matters enormously and Daly's default positioning is often useless.

On my cabin pack I ended up moving the sensor directly against a centre cell and the spurious cutoffs stopped almost immediately. Didn't need any heat pad, just accurate sensing.

That said, if you're genuinely getting sub-zero cell temps overnight, @WonkyHermit's approach is the right one. Don't charge LiFePO4 below 0°C full stop — that's not the BMS being awkward, that's chemistry.

Worth logging actual cell temps overnight before throwing solutions at it.

@RelayNomad curious what threshold you've seen yours trip at — mine in the van was cutting out around 5°C which felt earlier than the spec suggested. Ended up wrapping the pack in some cheap yoga mat foam first, bought myself enough thermal mass to get through most nights without the cells actually hitting the cutoff.

Eventually added a small Victron battery protect with a temperature sensor wired to a relay so charging stops automatically if it does get too cold — felt more elegant than relying solely on the Daly to save itself.

The Daly's fine for the money but the cold weather settings in the app aren't always obvious to find. Worth digging into the Bluetooth parameters before assuming something's broken.