Winter driving's brutal for keeping anything topped up tbh. Short runs to the shops or a local site barely gets the alternator doing anything useful before you're parked back up again.
I'm on a static so don't have this exact problem myself, but I went through similar headaches before I settled — had a van for a couple of years and the leisure battery was constantly sulking through November to February.
Few things that made a difference back then:
- B2B charger (Battery to Battery / DC-DC charger) — proper game changer. Victron Orion-Tr Smart was what sorted mine. Unlike a basic split charge relay, it actually pushes a proper charge profile into the leisure battery even on short runs
- Solar on the roof — even a couple of 100W panels do something on winter days, every little helps
- Check your battery chemistry — AGM and lithium respond very differently to partial charging. If you're on an old flooded lead acid, it's probably suffering more than it needs to
The real issue with short drives is you're never getting above 80% before you stop, and that cumulative undercharging kills batteries over a season.
Anyone running a Victron Orion or similar B2B — what settings are you using? Curious whether people are tweaking the absorption voltage for winter or just leaving it on defaults.
Also worth checking if your vehicle's alternator is smart/variable voltage — some newer ones confuse basic relays and you get almost nothing going to the leisure bank anyway.
