Anyone else built a dedicated emergency power kit that lives permanently ready to go?

After losing power for three days during a particularly savage Scottish storm last winter, I stopped relying on "I'll sort something out if it happens again" thinking. Built a small dedicated kit that lives in a weatherproof box in the cabin's utility room — never touched for anything else, always charged, always ready.

The setup is fairly modest: a 100Ah Fogstar Drift LiFePO4, a Victron SmartSolar 100/20, two 175W Renogy panels that can be deployed on the roof or propped outside, and a Victron Phoenix 12/800 inverter. Feeds the fridge, a couple of LED circuits, the router, and the water pump. That's it. Total cost was around £650 spread over a few months of buying bits.

The thing I keep wrestling with is self-discharge and maintenance. The Fogstar sits at storage charge (around 50%) and I top it up via a small trickle from one panel keeping it honest, but I've never actually needed it in anger yet. My worry is pulling it out in a crisis and finding something's degraded or a connection's gone green.

Has anyone got a reliable "test and verify" routine for a standby kit like this — something you actually stick to rather than meaning to do every few months and forgetting?

Gazza55 | 847 posts

@LochWalker three days in a Scottish winter with no power would sharpen anyone's thinking pretty sharpish!

I did exactly this about two years ago after a nasty storm here in Cumbria. My kit lives in a dedicated plastic storage box in the utility room - 100Ah lithium battery, a small 500W inverter, pre-cut cables with Anderson connectors already attached, and a folding 100W panel leaning against the wall right next to it. Everything's labelled clearly so my wife can operate it without me if needed.

The key thing I'd stress is testing it regularly. Mine gets a full run-through every three months, otherwise you discover problems at exactly the wrong moment. I also keep a laminated instruction sheet inside the lid - sounds daft but stress does funny things to your brain at 2am in a blackout!

DodgyRoamer | 1,203 posts

@LochWalker similar wake-up call here after a 36-hour outage — now I keep a dedicated 200Ah LiFePO4 (Fogstar Drift cells, top-balanced and boxed up properly) paired with a Victron MultiPlus-II permanently float-charged off the mains. Critical circuits only: fridge, a couple of sockets, router, and the combi boiler's control board.

Key thing most people miss — the boiler. Yours is likely drawing 150–200W when firing. Size your inverter accordingly or you'll be cold as well as dark.

Pre-wired a transfer switch so there's zero faffing when the grid drops. The whole thing sits in my garden office, does double duty keeping that space powered day-to-day, and has genuinely been tested twice this winter already.

Separate the "emergency kit" mentally from your main solar setup if you have one — contaminating the two means neither works optimally when it matters.

BigAl27 | 312 posts

Yeah, my shepherd's hut forced me into this mindset from the start — no grid connection means you just have to think this way.

Dedicated kit lives in a plastic Really Useful Box: Fogstar 100Ah lithium, small Victron MPPT, a folding 100W panel I can sling on the roof, and a basic inverter. Everything pre-wired with Anderson connectors so it's genuinely grab-and-go in under two minutes.

Key thing people overlook — test it regularly. Mine gets a full cycle every couple of months so I'm not finding out the battery's degraded when I actually need it.

@LochWalker three days in Scotland in winter is no joke. What are you running off yours — just lighting and phone charging, or something more ambitious?

VoltWendy | 634 posts

@BigAl27 the shepherd's hut life really does rewire your brain around power resilience, doesn't it.

Mine lives in a Peli case — Fogstar Drift 100Ah LiFePO4, a compact Victron 375VA inverter, and a little MPPT controller all wired to Anderson connectors so everything just plugs in rather than me fumbling with terminals at midnight in a panic.

The key thing nobody mentions: I test it on the first of every month. Run the kettle, charge some devices, make sure the battery's topped up. Takes twenty minutes.

Discovered during one test that a connection had corroded enough to cause a voltage drop. Glad I found that on a dry Tuesday afternoon rather than during the next January howler.

The kit that never gets tested is just expensive false comfort.

LisaMorgan59 | 847 posts

Great thread @LochWalker — Scottish winters really are the best teacher for this sort of thing, aren't they!

Mine lives in a dedicated plastic storage crate in the utility room: a 100Ah LiFePO4 battery with a small inverter permanently wired to it, a folding 60W panel leaning against the wall beside it, and a printed laminated card on top listing exactly what it can run and for how long. That last bit sounds daft but when you're stressed during an actual outage, having the numbers right there saves a lot of faff.

I top the battery up with a trickle charge every couple of months so it's never sitting flat. The whole thing is ready to deploy in about ten minutes. Nothing clever, nothing expensive — just properly maintained and genuinely ready rather than "probably fine somewhere in the garage."