Inselanlage in Ferienhütte

Anyone else got a Victron SmartSolar MPPT setup running at a holiday cabin or seasonal property they abandon for months at a time?

Got a similar rig to what someone was describing over on a German forum — MPPT 150/35, a Multiplus 48/3000/35, and a small Pylontech bank (mine's two US2000s rather than three, because my wallet wept at the third one). Works a treat when I'm there, but leaving it unattended over winter gives me actual nightmares. 🏚️

The big question I keep wrestling with: what's the safest way to leave the system in a low-power "hibernation" mode when you're locked out for six months? Do you:

• Leave the Multiplus in storage mode and pray the solar keeps the Pylontechs happy?
• Set aggressive low-battery disconnects via the Color Control GX and hope for the best?
• Just isolate everything and accept the Pylontechs won't thank you for a semi-discharged winter?

I've read Pylontech themselves say don't store below about 25%, but in a Scottish bothy with two weeks of November cloud cover, "plan" and "reality" are strangers to each other.

Remote monitoring via VRM helps obviously — at least I can watch the disaster unfold from my sofa — but I'd love to hear from anyone who's genuinely left a Victron/Pylontech system to fend for itself through a British winter without returning to a very expensive pile of sulphated regret.

Motorhome crowd, I know you've got opinions on this too — come argue with me.

Yeah, exactly this situation with my cabin setup.

Few things worth knowing for long-term unattended Victron MPPT installs:

• Enable absorption/float properly — default settings can be aggressive on lithium if you're using Fogstar or similar LiFePO4
• Set up VRM portal alerts so you get an email if voltage drops unexpectedly
• Battery disconnect threshold matters a lot — I have mine set to cut at 20% SOC so nothing's sitting at rock bottom for weeks

The SmartSolar handles being left alone surprisingly well tbh. Mine ran through a full Scottish winter unattended with minimal drama. Panels just kept ticking over even in low light.

What battery chemistry are you running? That changes the advice quite a bit. Lead acid behaves very differently from lithium over a long idle period.

Big yes from me — got a Victron SmartSolar 100/30 running my garden office and a separate shepherds hut setup, both unattended for stretches.

One thing I'd add that nobody's mentioned yet — the VRM portal is genuinely brilliant for keeping an eye on things remotely. Set up alerts for low battery voltage and you'll get an email before anything goes properly wrong.

Also worth enabling scheduled charging via the app if you've got any grid top-up option, so the batteries don't sit at a low state of charge for weeks on end. Lithium especially hates that.

My Fogstar batteries have been solid through winter with minimal panels hitting them — Victron's absorption/float settings kept everything ticking over nicely without me being there. 🔋

One thing I'd add from my motorhome setup that translates well to unattended installs — the VE.Direct to Bluetooth dongle is worth having even if you've got a SmartSolar with built-in Bluetooth. Gives you a proper data log you can review remotely rather than just a live snapshot.

Also worth checking your battery absorption/float voltage settings are appropriate for the chemistry you're running. I had Fogstar lithium in mine and the default lead-acid profile was silently doing damage over a long winter. Not catastrophic, but not ideal.

If the cabin genuinely sits empty for months, consider whether the parasitic draw from the MPPT itself plus any BMS is actually exceeding your winter solar harvest on shorter days. Worth modelling before you leave it.

My garden office runs unattended on a Victron SmartSolar 75/15 for weeks at a time and honestly the biggest "gotcha" I never see mentioned is making sure your battery absorption voltage is properly matched to your actual battery chemistry — had my Fogstar Drift lithium sitting in a slightly wrong profile for three months before I noticed, which is three months of your cells quietly having a bad time.