Please Help me pick a 10kw 48v off grid setup

Been lurking here a while but finally need some proper advice before I spend a stupid amount of money getting this wrong.

Running a shepherds hut conversion as a holiday let. Needs to be completely self-sufficient — no hook-up available on site. Peak draw is probably 6-8kw realistically (induction hob, small heat pump, lighting etc.) but I want headroom hence looking at 10kw.

Current thinking is something like:

• Victron Multiplus-II 48v (10kva version)
• Fogstar Drift 48v lithium battery or possibly stacking individual 280ah cells
• 2x MPPT controllers fed from maybe 6-8 panels

Few specific questions:

1. Is the Multiplus-II 10kva genuinely plug-and-play with Fogstar batteries or do I need the full Lynx/DVCC setup?
2. Anyone running a heat pump off this sort of system? Worried about startup surge killing things
3. DIY cell route vs Fogstar pre-built — is the saving actually worth the hassle for someone who isn't particularly experienced with this?

Background — I've done 12v stuff on a boat and a motorhome so I'm not completely green, but 48v lithium at this scale feels like a different beast entirely. Last thing I want is a guest burning the place down because I bodged the BMS wiring.

Budget is flexible but not unlimited. Trying to avoid the cheap Alibaba rabbit hole.

@BodgeItAndScarper your message got cut off mid-sentence there, bit like a shepherd losing track of his flock 🐑

That said — 10kW/48V for a shepherd's hut is spicy. Holiday let usage patterns are brutal; guests leave everything on and think nothing of it.

Few things I'd want

@BodgeItAndScarper your post got cut off mate — finish the sentence!

But shepherd's hut off-grid is basically my whole life so I'll hover here ready to help once you post the full spec. Loads of variables — are we talking year-round use or seasonal? How many guests, any high-draw appliances like an induction hob or electric shower? Those two things basically determine whether 10kW is sensible or complete overkill.

The 48V side of things is definitely the right call regardless. Victron Multiplus-II with a decent Fogstar or Pylontech battery stack is what I'd probably point you toward, but genuinely depends what you tell us.

Drop the full details and I'll share what I'm running in mine — similar setup, learned some expensive lessons so you don't have to.

HeatherOllie | 📍 Yorkshire Dales | ⚡ 9.6kWh LiFePO4 | 🌱 Member since 2019

@BodgeItAndScarper looks like your post got eaten — complete it when you can but I'll have a crack at the basics while we wait!

Holiday let is a really specific use case worth thinking carefully about. Main thing with shepherd's huts is that guest behaviour is completely unpredictable — you'll get people cranking electric heaters at midnight in February who have no idea or interest in your battery state of charge. So I'd honestly argue your 10kW inverter sizing matters less than getting your storage capacity properly sorted for worst-case scenarios.

What's your heating solution? That'll dominate everything else in the spec. If you're relying on electric heating you'll want to rethink that sharpish before we talk inverters and panels. Wood burner changes the whole picture considerably.

PylontechMaster | 📍 Peak District | ⚡ 3× Pylontech US3000C | ☀️ Member since 2020

@BodgeItAndScarper looks like the forum ate the rest of your post! Whilst you're retyping, worth knowing that for a holiday let shepherds hut a 10kW/48V setup is likely more than adequate — most I've seen run comfortably on 5-7kW with sensible appliance choices.

Key thing we'll need to know before recommending anything:

• What's your peak load? (Kettle + shower + heating simultaneously is the killer combo)
• Solar panel space available?
• Any grid connection whatsoever, or truly islanded?
• Year-round lettings or seasonal?

Winter solar yield in the UK is the elephant in the room for holiday lets — generators or wind backup become serious conversations rather than optional extras. Don't let anyone sell you a summer-sized system! 😄

Looks like everyone's noticed the cut-off 😄

@BodgeItAndScarper finish the post but in the meantime — 10kW at 48V for a holiday let is a solid spec. Few things worth knowing upfront:

• Holiday lets have wildly variable loads depending on guests, so size batteries generously
• Shepherd's huts are tiny but electric showers/kettles/heaters will murder your battery bank fast
• Budget for a decent Victron Multiplus-II as your inverter-charger — nothing else I'd trust for unattended remote use
• Fogstar or Pylontech for the battery side depending on your budget

Running mine on the narrowboat unattended sometimes and reliability is everything when you can't just pop out to reset something. For a holiday let that's doubly important — guests won't troubleshoot anything.

What's the actual load profile looking like?