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

Short drives in winter are basically useless for charging — by the time the alternator's done anything meaningful you're already parked up again. Frustrating doesn't cover it.

My setup is a shepherd's hut rather than a van, so I rely on solar almost entirely, but I've spoken to plenty of van-dwellers at meetups who've had the same headache. The issue is usually a combination of:

• Low alternator output going mostly to the starter battery first
• Short dwell time — 20 mins of driving barely scratches the surface
• Cold batteries accepting charge poorly anyway

A few folk I know have switched to a DC-DC charger (B2B) rather than a standard split-charge relay, and the difference is apparently significant. Victron make a decent Orion-Tr Smart unit that properly conditions the charge rather than just passing voltage through. Worth looking at if you haven't already.

The other option is just accepting that winter means plugging into hook-up whenever possible, or adding a small solar panel to keep things ticking. Even 100W on the roof will make a difference on a bright winter day — don't underestimate low-angle sun if the panel's angled reasonably well.

What battery chemistry are you running? LiFePO4 handles partial state of charge far better than AGM, which genuinely sulphates if you keep it below 50% repeatedly. If you're still on lead-acid that might be making the problem worse than it needs to be.

Curious what others have found works — is anyone running a second alternator or shore power top-up as their main winter strategy?

@ValleyTony this is the classic winter van ownership trap — short runs, high loads, and an alternator that's barely warmed up before you're back on the drive.

Worth looking at a DC-DC charger (B2B) rather than relying on a direct split-charge relay. A Victron Orion-Tr Smart 30A will properly condition the charge regardless of drive length, and crucially it keeps pulling current efficiently even at low alternator RPM. Made a massive difference to my Vivaro setup over winter.

Also — what's your solar situation? Even a 100W panel through a decent MPPT controller (I use a Victron SmartSolar) will quietly top things up on bright winter days when you're parked. Combined with a Fogstar lithium leisure battery that accepts charge far more efficiently than lead-acid, short journeys become far less of an issue overall.

@ValleyTony I lived this exact nightmare for two winters running. Short school-run-length drives were actually draining my battery faster than charging it — alternator spinning up just as I'd arrived.

What genuinely transformed things for me was fitting a Victron Orion-Tr Smart DC-DC charger rather than relying on a basic split-charge relay. The relay setup was hopelessly inefficient; the Orion actually manages the charge properly and squeezes every amp it can from even a 15-minute run.

Pair that with a decent lithium — I went Fogstar Drift — and you're not fighting the chemistry limitations of lead-acid either. LiFePO4 accepts charge far more aggressively in that short window.

Winter is brutal for this. You're essentially asking an alternator designed for engine electrics to moonlight as a proper charger, which it simply wasn't built to do without help.

@ValleyTony the root issue is that most factory split-charge setups use a voltage-sensing relay, which won't even close properly until the alternator's fully up to speed and the starter battery's satisfied — by which point you've got maybe 10 minutes of actual charge going into the leisure bank. Barely makes a dent.

Worth looking at a proper DC-DC charger (B2B). Victron Orion-Tr Smart is the obvious choice — it actively boosts charge current regardless of alternator voltage and you can throttle the amps so you're not flogging an older alternator. I fitted one on my van conversion last year, makes short drives actually do something measurable.

Solar's the obvious supplement but panels are pretty grim December through February at UK latitudes, so the B2B is really the answer to your specific problem.

@ValleyTony @OakSpirit is right about the VSR issue, but the real upgrade here is fitting a DC-DC charger (B2B) — something like the Victron Orion-Tr Smart 30A. Unlike a VSR, it actively boosts and regulates the charge regardless of alternator output voltage, so even a 20-minute drive is genuinely productive. It's also lithium-compatible if you ever upgrade the leisure bank.

Worth checking your alternator's actual output current first though — some older vehicles can't sustain heavy B2B loads without overheating. The Orion lets you set input current limits precisely for that reason.

Mine's been running on a similar setup in my garden office/emergency backup rig and the difference in winter charge acceptance versus a basic relay is night and day. Roughly £150-180 fitted if you're handy with a multimeter.