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

Not a motorhome owner myself, but I run a fairly sizeable off-grid setup for a garden office so I've picked up a fair bit about battery management in low-light/low-input scenarios — and the physics are basically the same problem.

The short drive issue is brutal in winter for a few reasons:

• Alternator charging is inefficient for lithium unless you've got a proper DC-DC charger (B2B) in the circuit — a basic split charge relay just won't cut it
• Cold temperatures hammer your battery's acceptance rate anyway, so even if the alternator is pushing amps, the battery may not be taking them efficiently
• Short runs mean the alternator barely gets up to full output before you've parked up again

If you're running a lead-acid leisure battery, honestly it might be worth looking at whether lithium (LiFePO4) would help — Fogstar do decent cells at reasonable prices. The charge acceptance on lithium is dramatically better, so you'll get more usable energy from those short sessions.

Also worth checking: is your B2B charger (if you have one) actually sized correctly? A lot of people fit a 20A unit when a 40A would make a real difference on a 20-minute commute.

What battery chemistry and charging setup are you currently running? That'd help narrow down whether it's a hardware fix or more of a usage pattern issue. Curious what others on here are doing to bridge the gap — solar on the roof presumably helps in summer but doesn't solve winter shortfalls.

@AlexPalmer60 mate you're posting about motorhome split charging in a motorhome forum from a garden office — bold energy, much like a 10W panel in December trying to run a kettle.

@AlexPalmer60 short answer — yes, it's a nightmare in winter.

The problem isn't just low light, it's that a 20-minute school run barely gets the alternator up to proper charging voltage before you've stopped again. Running a Victron DC-DC charger sorted it for me — proper controlled charge rather than relying on the old split-charge relay which is basically useless in this scenario.

Also worth checking your battery chemistry. If you're still on a flooded lead acid, you're losing a chunk of that marginal input just to internal resistance. Switched to Fogstar lithium last year, night and day difference in how it accepts charge from short runs.

@OffGridHamish to be fair, the physics don't care what forum you're on.

@AlexPalmer60 bold of you to wade into motorhome territory from a garden office 😄 — @OffGridHamish already clocked that one

Closest I get to a moving vehicle is my shepherd's hut, and even that doesn't charge itself by driving to Tesco.

Genuine point though — if the

@OffGridHamish @ExJoiner32 to be fair, a garden office is basically a motorhome that's given up on travel and committed to one spot 😄

But genuinely — the short-drive problem is brutal in winter regardless of your setup. Your alternator's barely warming up before you're parked again. A B2B