Anyone else running a Victron SmartSolar in low-winter-sun UK conditions — what MPPT settings are you using?

Just fitted a 200W Renogy panel on the narrowboat roof (tiltable mount, south-facing when moored up) feeding into a Victron SmartSolar 100/20 and a 200Ah Fogstar Drift lithium. December has been... humbling. Seeing maybe 20–40W peak on a good overcast day, and the controller's absorption phase seems to kick in embarrassingly early.

Currently running the default lithium preset (14.2V abs, 13.5V float) but wondering if tweaking absorption voltage up to 14.4V and shortening the absorption time would squeeze more back in before the sun gives up entirely. Battery's sitting at 60–70% most mornings which isn't ideal for the diesel-free aspiration.

Anyone found a sweet spot for UK winter MPPT programming, especially with lithium? Panels are flat-mounted for now — even tilting to 60° on clear days only gets me to about 55W, which on a narrowboat feels like a moral victory.

Same setup basically — SmartSolar feeding a Fogstar Drift on the boat.

Few things that made a real difference for me in winter:

• Set absorption voltage to 14.2V rather than the default 14.4V (Fogstar's own recommendation for longevity)
• Tail current down to 2% so it doesn't hang in absorption forever on a grey day
• BatteryLife disabled — pointless with lithium, just gets in the way

The tiltable mount is your biggest win tbh. I go steeper than you'd think — nearly 60° in December to catch the low sun angle. Genuinely noticeable difference vs flat.

Also worth enabling the equalization panel in VictronConnect just to monitor things — not that lithium needs it, but the data's useful.

What's your tail current set to currently?

@ExPostie86 welcome to the forum, great first post! 🙌

Running almost identical kit in my motorhome — SmartSolar 100/30 into a Fogstar Drift 100Ah. December really does test your patience!

Few extra bits worth trying:

• Tilt that panel aggressively — I mean properly steep, like 60-70° in winter. Low sun angle makes a massive difference
• In VictronConnect, check your absorption voltage is set correctly for the Fogstar (they publish exact figures on their site)
• Enable Equalization OFF if it's showing — lithiums hate that

The Fogstar Drift is brilliant but it's unforgiving if settings are wrong. Worth dropping Fogstar's support a message — they're genuinely helpful and usually reply same day.

Keep us posted on how you get on! Narrowboat solar is a brilliant use case 🚤