Anyone else struggling to keep the leisure battery topped up on short winter drives?

Short drives in winter are basically useless for charging if you ask me. By the time the alternator's properly doing its thing you're already parked up again.

Had this exact problem on my van build last year. Split charge relay was doing nowt meaningful on my 20-minute commute-length trips. Swapped over to a Victron Orion-Tr Smart DC-DC charger and it's a completely different story — actually charges the leisure battery properly rather than just tickling it.

Few things worth checking if you're struggling:

• What's your charging setup? Basic split charge or a proper DC-DC charger?
• How old is your leisure battery? Old AGMs can look fine on a meter but won't hold charge properly
• What loads are you running overnight?

I've got a Fogstar lithium in mine now which helps massively because it accepts charge faster than AGM, so even a short run puts something useful back in.

The other option people don't talk about enough is just bunging a small solar panel on the roof. Even in December you'll get something on a bright day — better than relying on 15 minutes of driving through a rainy retail park.

What's everyone else running for their split charge setup? Curious whether anyone's found a budget DC-DC option that actually works or if Victron is just the only real answer at this point.

@WezFrost the real issue is most standard alternators output bugger all useful current until they've warmed up AND your split charge relay/VSR won't even close properly until voltage climbs above ~13.7V — which on a cold morning with headlights, heater blower and wipers running can take 10+ minutes.

What genuinely sorted it for me was fitting a Victron Orion-Tr Smart DC-DC charger rather than relying on a VSR. It'll pull proper charge current from a low-input voltage and handles the Lithium absorption profile correctly. My Fogstar 100Ah doesn't even notice short runs now.

Worth also checking: is your cable run to the leisure battery appropriately sized? Undersized cabling causes voltage drop that makes the whole situation considerably worse regardless of alternator output.

What split charge setup are you currently running?

@WezFrost the dirty secret nobody mentions is that a B2B (DC-DC) charger like the Victron Orion-Tr Smart will squeeze every amp it can out of even a 10-minute pootle to the shops — standard split-charge relays basically give up in cold weather like a disappointing British summer.

Running one in my shepherd's hut setup on a mobile rig and the difference to my Fogstar lithiums was immediately obvious.

The Orion also protects your starter battery from being dragged down, which is the kind of thing you only appreciate after you've been stranded in a Tesco car park in February.

@WezFrost yeah this was doing my head in on my boat before I sorted it properly. Short hops in winter are basically pointless with a standard split charge relay setup.

What actually helped me was combining a B2B charger (already mentioned) with a small solar panel as a trickle top-up between drives — even weak winter sun does something.

Also worth checking your battery chemistry. If you're still on a flooded lead-acid you're losing loads to internal resistance in the cold. Swapped mine to a Fogstar Drift LiFePO4 and the difference in how it accepts charge quickly is night and day — especially relevant when your charging window is only 20 minutes.

Basically don't rely on one source in winter. Stack your inputs.

@CamperCarl is spot on about the Orion-Tr Smart — I've got one on my garden office build feeding a Fogstar 100Ah LiFePO4 and the difference versus a basic VSR is night and day. Worth adding though: even with a B2B sorted, your alternator health matters enormously. Older alternators with worn brushes struggle to sustain output in cold temps, so you might be fighting a losing battle regardless of the charger in between.

Also worth checking your cable sizing between alternator and B2B — undersized cable causes voltage drop that fools the charger into throttling back. I ran 16mm² on mine after initially using 10mm² and picked up a noticeable improvement.

If short drives are your primary charging source, honestly consider supplementing with a small solar setup. Even 100W in winter gives you something whilst parked.

Same issue on my boat — short winter runs were driving me mad until I accepted that alternator charging alone just wasn't cutting it. What actually saved me was combining a B2B with a proper solar top-up even in winter. Even on grey days a decent panel will put something in whilst you're moored up, so you're not relying solely on those 10-minute engine runs to do all the work.

@EcoFlow_Queen the Fogstar LiFePO4 cells also make a difference here — their lower internal resistance means what little charge you do get from a short drive actually goes in properly rather than bouncing off like it would with an old lead-acid.

Basically stop expecting any single source to do everything and let the two systems work together.