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

Fitted a Victron Orion-Tr Smart DC-DC charger two winters ago and suddenly realised my alternator had been doing absolutely nothing useful for 15 years — brilliant bit of kit, genuinely changed everything.

The problem with short runs is dead simple: your split-charge relay (if that's what you're still running, bless you) barely gets the battery above "slightly less dead" before you're back on the drive making a brew. The Orion actually thinks about what it's doing, unlike me at 7am.

My setup is a 200Ah Fogstar Drift LiFePO4 in the back, and even on a gloomy January school-run distance, I'm pulling decent amps through properly. Worth noting the Orion has a Bluetooth app so you can sit there watching electrons move about instead of talking to your passengers — a genuine improvement on most conversations.

Few questions worth discussing though:

• Anyone running solar alongside their DC-DC in winter? My 200W panel is basically decorative from November to February 😅
• Split-charge relay diehards — what's your actual justification at this point?
• Anyone tried the Sterling Power B2B as an alternative? Curious how it compares

The real villain here is British winter in general — short days, short drives, everything wanting power for heating. My leisure battery used to spend January looking like a disappointed relative.

What are others doing? There must be someone on here still insisting a £12 relay from eBay is "doing the job fine."

@RetiredNurse49 mine sat doing nothing for years too, except apparently heating the engine bay like a very expensive radiator 🔥 — slapped a Victron Orion on the van last February and now even my sad little 20-minute school run shuffle actually moves some electrons into the Fogstar lithium I fitted in the cab-over, which is frankly miraculous given I once drove to Scotland and back on a trickle.

@RetiredNurse49 Similar situation here with the van. Spent about three winters scratching my head wondering why my 200Ah Fogstar lithium never got above 60% after a run, then discovered the old split-charge relay was basically decorating the engine bay. Swapped it out for the Orion-Tr and suddenly short December runs between sites actually meant something again.

The real kicker — and this is what nobody tells you — is that the B2B charger also protects the starter battery properly when temperatures drop. Found that out the hard way one January morning in a layby somewhere deeply unglamorous.

Worth checking your cable gauge too if you're not seeing the full benefit. Undersized wire will throttle the whole thing regardless of how clever the charger is.

@RetiredNurse49 worth noting the Orion-Tr Smart has a "engine running detection" threshold you can configure — default is something like 13.2V but on older alternators with dodgy regulation you may need to adjust that downward or it simply won't trigger. Caught me out on the boat before I twigged what was happening.

Also — and this is the pedantic bit — are you running it in isolated or non-isolated mode? Matters quite a lot depending on your chassis earth configuration. Non-isolated is fine for most motorhomes but get it wrong and you're creating a ground loop nobody wants.

For winter specifically: shorter charge acceptance window means your bulk-to-absorption transition matters more. Check your absorption voltage is actually set correctly for your battery chemistry. Fogstar Drift cells are particularly fussy about this in cold temperatures.

If your alternator's been freeloading longer than your brother-in-law, the Orion-Tr Smart will sort it — mine's been quietly stuffing electrons into a Fogstar Drift 100Ah all winter like a very diligent squirrel, even on a 20-minute Lidl run. 🐿️