Anyone else struggling to keep the leisure battery topped up on shorter winter trips?

Winter sun in the UK is basically decorative at this point — my Renogy panels spend November to February looking pretty and contributing roughly the same energy as a disappointed sigh.

Switched to a Fogstar Drift 100Ah LiFePO4 last season and the state-of-charge anxiety is real when you're only doing weekend hops. The higher efficiency helps compared to my old AGM, but if you're not driving decent distances to let the alternator do its thing, you're still in trouble.

Few things that actually made a difference for me:

• DC-DC charger (Victron Orion-TR Smart) — actually charges the leisure battery properly rather than relying on the van's split-charge relay doing approximately nothing
• Cutting parasitic loads ruthlessly — my old Truma control panel was quietly sipping away like it owned the place
• A small 240V hookup top-up when parked at home before departure

My shepherd's hut setup has the same problem in reverse — loads of panel capacity but the batteries barely need it when nobody's staying. Still, the hut taught me that good battery monitoring is half the battle; you can't fix what you can't see, so a Victron BMV-712 is genuinely worth every penny.

What's everyone else running? Anyone found a solar solution that actually works in a British January, or are we all just accepting defeat until April?

NickThompson65 | 847 posts | West Yorkshire

@PanelRoger Ha, "disappointed sigh" is genuinely the most accurate description of UK winter solar I've ever read. 😄

One thing that transformed my setup was fitting a proper DC-DC charger between the alternator and leisure bank. Even a 45-minute motorway run will push a decent chunk back in when the panels are being useless. Sterling and Victron both do solid units.

Also worth checking your actual panel orientation — I tilted mine more steeply for winter (closer to 60°) and picked up a noticeable improvement over lying flat. Not miraculous, but every amp counts between November and February.

What capacity are you running? Sometimes the real answer is just "bigger battery" — lithium holds its charge so much better over several days of sitting idle compared to AGM.

AngliaNomad | 312 posts | Norfolk/Everywhere

@PanelRoger Completely feel this. My workaround for shorter winter trips has been running the engine for 20-25 minutes each morning with a decent B2B charger fitted — gets far more into the battery than solar ever would in December. Combined with being brutal about consumption (LED everything, 12v blanket instead of heating overnight), I've found I can comfortably stretch a 100Ah lithium through a long weekend without shore power.

The other thing worth considering if you haven't already — a small mains charger and grabbing hookup even occasionally at a site you'd normally go without. Couple of hours tops up what a whole grey December day couldn't manage.

What battery chemistry are you running? Makes a big difference to how aggressively you can actually use what you've got stored.

MarineAlan | 203 posts | Array

Interesting thread. Has anyone actually quantified what they're losing versus what the alternator is realistically replacing on a 2-3 hour winter drive?

I've been logging my Victron battery monitor data across a few short trips and the numbers surprised me — the absorption stage barely kicks in before I'm parked up again.

Quick questions for those running split-charge setups:

• What's your DC-DC charger rated at?
• Are you monitoring state-of-charge properly or just guessing from voltage?

Also @AngliaNomad — curious what your workaround actually is, your reply got cut off.

Welcome to anyone new finding this thread via search, by the way — winter charging is one of those topics that looks simple until you dig into it, so keep the questions coming.

LazySparky | 1,204 posts | Scottish Borders

@MarineAlan good shout actually — rough numbers for anyone wondering: at 52°N in December you're looking at maybe 1-2 peak sun hours on a decent day, versus 5-6 in summer. So a 200W panel might realistically give you 200-400Wh daily if you're lucky and parked perfectly. Meanwhile a typical motorhome fridge alone can chew through 300-400Wh overnight.

The maths just don't work for anything beyond a night or two without an alternative source. Sterling B2B chargers off the vehicle alternator are worth serious consideration for winter — even a 20-30 minute drive genuinely moves the needle. Not glamorous, but it keeps things honest when the sun's basically phoning it in from behind a cloud somewhere over Iceland. 🙄

TimTaylor | 847 posts | Derbyshire/Peak District

@LazySparky those rough numbers are spot on in my experience. One thing nobody's mentioned yet — don't overlook your habitation loads during winter. You're running the heating fan, lighting, and phone charging far longer than summer trips because you're stuck inside more and the nights are brutal. I switched to LED throughout last year and it made a genuine dent.

Also worth checking your battery terminals and connections before blaming solar output entirely — I chased a "winter charging problem" for two seasons before discovering a corroded negative terminal that was robbing me of efficiency year-round. Embarrassing in hindsight but apparently common. A decent battery monitor like a Victron BMV will show you exactly where you stand rather than guessing.