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

Same battle every November onwards without fail. The alternator's doing its best but short runs to the farm shop or even a 40-minute blast up the A-road barely scratches the surface when the Fogstar 100Ah lithium is sitting at 60% and the heating's been running overnight.

The real turning point for me was fitting a Victron Orion-Tr Smart DC-DC charger a couple of winters back. Before that I was relying on a basic split-charge relay which, with a lithium battery, is basically useless — the relay sees voltage and thinks the job's done when it's barely delivered anything meaningful.

The Orion changed everything. Even a 25-minute drive now puts back a genuine 20–25Ah rather than the token gesture I was getting before. You can watch it working properly through the VictronConnect app, which is oddly satisfying on a cold morning.

That said, I've still added a 200W Renogy panel on the roof for the static days because around December and January in the Midlands, solar is barely worth mentioning — you might scrape 15–20W on a bright day if you're lucky.

Curious whether others are managing purely on drive charging or whether you've accepted that a mains hookup or a DC-DC is basically essential for year-round use without shore power.

Also wondering if anyone's experimented with a second alternator setup — seems like overkill but I've seen a couple of conversion threads mentioning it for exactly this kind of situation.

What's everyone's current winter charging strategy? Are you adapting routes just to get more drive time in, or have you found a smarter solution?

@Tel1961 know this pain intimately. The core issue is that your alternator voltage (typically 14.2–14.4V) is fine for AGM but a 200Ah Fogstar Drift LiFePO4 wants proper bulk charging — and your B2B charger's amperage multiplied by 40 minutes simply isn't moving the needle meaningfully.

My fix was fitting a Victron Orion-Tr Smart 30A DC-DC isolated B2B. Even a 25-minute motorway run now pushes 400–450Wh back in. The "engine running" detection via the ignition wire means it ramps immediately rather than fafffing around.

Worth checking:

• Cable gauge between alternator and B2B (undersized cable kills efficiency)
• Whether your van's smart alternator is throttling output via the ECU

Longer term, even a modest 200W rooftop panel from Renogy transforms winter top-up completely — alternator alone in November is genuinely a losing battle without supplementary solar.

@Tel1961 @SprinterProject — worth looking at a DC-DC charger if you haven't already. A Victron Orion-Tr Smart 30A transformed my winter charging completely. Rather than just floating off the alternator voltage, it actively boosts and regulates the charge properly for lithium chemistry.

Even a 20-minute run will push meaningful amps into the leisure bank rather than just tickling it.

The other thing I'd add — check your cable run from the vehicle battery to the leisure setup. Voltage drop on undersized cable is silently killing your charging efficiency before it even reaches the Fogstar. I found nearly 0.4V drop on mine before I uprated to 10mm² throughout.

@Tel1961 this was the exact rabbit hole I fell down two winters ago with my Transit-based build. Forty minutes up the A35 barely moved the needle on my Fogstar 460Ah, and I was scratching my head wondering why.

What nobody mentioned to me at the time — and @MarineMike and @SprinterProject are both right about the DC-DC route — is that even after fitting the Orion-Tr, your parking habits matter enormously. I started deliberately choosing the furthest car park space, adding an extra ten minutes each run. Daft as it sounds, those stolen minutes stack up across a week of errands.

The real game-changer though was a 200W panel on the roof. Even flat December light in Dorset gives you something, and combined with the Orion it keeps the battle firmly in my favour rather than the battery's.

@MarineMike seconded on the Orion-Tr Smart — fitted one to the cabin's backup van setup last winter and it made a proper difference. Worth noting though, if you've got a smart alternator (most post-2015 vehicles do), make sure you're getting the isolated version rather than non-isolated. Caught a few people out on here before.

Also @Tel1961 — even with DC-DC sorted, short runs in deep winter are still a losing battle if you're drawing heavily overnight. Doesn't matter how good the charger is if the maths don't add up. Even a small panel on the roof pulling 20–30W on a grey day helps bridge the gap between drives.