Anyone else running Fogstar Drift lithium in a van? Tempted to swap out my AGM

Been running a 200Ah AGM bank in the van conversion for about three years now and it's starting to struggle — taking forever to charge and barely holding capacity overnight. Reckon it's on its last legs.

Looking hard at the Fogstar Drift 200Ah as a like-for-like swap. Price point seems reasonable compared to importing a Battle Born or going full Victron Smart Lithium. Already got a Victron SmartSolar 100/30 and a Victron Orion-Tr Smart for the alternator, so the BMS comms side should play nice.

Main thing I'm trying to work out is whether the Drift's built-in BMS handles the Victron charge profile properly out of the box, or if I need to faff about with custom settings. Also curious about real-world performance in cold weather — van sits outside all winter and I've read mixed things about LiFePO4 below 5°C.

Anyone made this exact swap or something similar? Actual numbers on charge acceptance and usable capacity in winter would be dead useful.

ClareCooper | 847 posts

@GoldenGaffer I made exactly this switch last spring — two 100Ah Fogstar Drifts replacing a tired AGM bank and honestly it's transformed van life. The usable capacity difference is night and day; you're actually getting what's on the tin rather than being scared to dip below 50%.

One practical thing worth knowing: check your alternator charging setup before you commit. The Drifts need a DC-DC charger (B2B) in between rather than connecting direct to the alternator — lithium's acceptance rate can cause issues otherwise. Victron Orion is the popular choice. Adds to the overall cost but it's the right way to do it properly.

Weight saving over AGM is a nice bonus too if you're watching your payload. What solar are you running currently?

Gazza89 | 412 posts

@GoldenGaffer Worth doing mate, I've had two 100Ah Drifts running in my Transit conversion since last autumn and honestly the difference is night and day. The usable capacity alone makes it worthwhile — you're actually getting what's on the tin rather than nursing an AGM to avoid hammering it below 50%.

One thing I'd flag that nobody seems to mention — double check your B2B charger settings if you're running one off the alternator. I had mine set up for AGM profile initially and it wasn't pulling anywhere near full charge current. Switched the profile over and suddenly everything clicked into place.

Weight saving was a nice bonus too, though that probably matters less in a van than a sailboat. What's your current charging setup like? Solar, alternator, hook-up?

MistyMender | 203 posts

@GoldenGaffer Three years from an AGM bank in a van isn't bad going to be fair, but yeah, the signs you're describing are classic end-of-life stuff. I swapped mine out for a single 200Ah Drift about eight months ago and the difference in usable capacity genuinely surprised me — getting into that lower 20% range without the voltage sag that was wrecking my inverter before.

One thing worth considering alongside the battery swap: your charging setup. If you're still running a standard split-charge relay rather than a DC-DC charger, you won't get anywhere near the charge speeds lithium is capable of. I fitted a Victron Orion at the same time and it transformed my solar and alternator charging efficiency massively. Bit more upfront cost but absolutely worth doing properly whilst you're already pulling the setup apart. 🔋

Ella1974 | 1,203 posts

@GoldenGaffer Three years is decent life from AGMs in a van environment — all that vibration doesn't do them any favours. I swapped to Fogstar Drifts about 18 months ago and the thing that surprised me most wasn't the capacity or charge speed (both brilliant, obviously), but how consistent they are across temperature swings. We do a lot of late autumn touring in Scotland and my old AGMs would absolutely tank in the cold. The Drifts have a low-temperature cutoff which initially worried me, but honestly it's rarely been an issue in practice. One thing worth checking before you buy — make sure your current solar controller and any DC-DC charger are actually lithium-compatible. Mine needed a firmware update before everything played nicely together. Happy to share my wiring setup if that'd help.

PanelSteve | 847 posts

Not a van man myself — I live on a narrowboat, so my Fogstar Drifts are bobbing about on the cut rather than rattling down the A14 — but the principle's identical. Vibration, damp, questionable charging sources... lithium just shrugs it all off.