Power cuts — what keeps your house going?

My setup here's been pretty solid through the winter outages we've had:

Got a 10kWh LiFePO4 bank (mix of Fogstar and Renogy cells) paired with a Victron Multiplus 48/5000. Solar's obviously limited this time of year, but I've rigged up a backup petrol genny for when the batteries dip below 20% — keeps things ticking over without hammering the cells.

The real game-changer was splitting the house into essentials and non-essentials. Boiler, fridge, lighting, and internet on the critical circuit. Everything else gets unplugged during extended cuts. Saves a fortune in battery drain.

EV charging goes on hold obviously — swapped to using the car as a portable power bank via the Victron now and then, bit handy that.

Main issues I've run into:

• Underestimating phantom loads (router was a culprit)
• Not enough redundancy with the genny (mate's got two now)
• Battery temp management in winter — insulation box helped loads

Reckon most people don't realise how quickly a decent lithium bank depletes if you're not disciplined about loads. Worth doing an audit of what actually needs power.

Curious what others are running — are you lot sticking with lead acid, or has anyone gone full lithium? And how do you handle the genny backup? Always wondering if there's a better setup than what I've cobbled together.

That's a decent foundation. The Multiplus 48/5000 is a workhorse—I've got the same inverter on my narrowboat setup and it handles the switching beautifully when grid drops.

One thing worth considering though: 10kWh sounds substantial until you're actually living through a proper winter outage. Solar generation in December/January is frankly dismal here in the UK. Have you got a backup gen set wired in? Even a modest 3-5kW petrol unit makes a massive difference when you're bridging those grey weeks. Mine's hardwired through a changeover relay into the Victron—no faffing about with cables.

Also worth stress-testing your actual discharge profile during an outage sim. Real-world consumption often surprises people once heating/cooking demands kick in. What's your typical winter draw looking like?

The 48/5000 really is bulletproof for that capacity—I've got one running my garden office setup and it just handles the switching seamlessly.

Where I'd push back slightly on winter reliance though: 10kWh sounds solid until you're actually rationing through a proper dark spell. I learned that the hard way with my cabin. Now I'm more focused on what actually uses the power in a cut scenario—heating's the killer. Are you running immersion backup, heat pump, or just accepting you'll be cold?

Also curious whether your Fogstar/Renogy mix is giving you any cell-matching headaches. I went full Victron LiFePO4 eventually just to reduce that variable, though I know others swear the mixed approach works fine.

The real test is whether you've actually lived through an outage with it or if this is theoretical. That changes everything about what you'd do differently next time.

Mate, 10kWh through winter is genuinely solid. The Multiplus is basically indestructible—I've had mine running my cabin for three years now and it's never complained once, even when I was being a numpty and drawing 4kW at 3am making coffee.

Real talk though—what's your charge strategy when the grid inevitably

Blimey, everyone's got a Multiplus these days—starting to think Victron should just rebrand it as the "British Off-Grid Standard." Jokes aside, @MarineGaz that 10kWh setup's properly impressive for winter. Question though—how's your battery management during those long grey spells when solar's basically decorative? I'm

The 48/5000 is genuinely the workhorse of the off-grid scene. That said, 10kWh through winter is cutting it fairly fine depending on your consumption profile—what's your average daily draw looking like?

I'm running a similar spec for my garden office (Victron 48/5000 with 8kWh LiFePO4), and the real limiting factor isn't the inverter, it's the charge controller bandwidth during those precious winter daylight hours. If you're relying solely on solar, you'll want to be realistic about December/January generation.

The mix of Fogstar and Renogy cells is sensible for cost management, though I'd suggest monitoring individual cell voltages across brands—slight chemistry differences can cause drift over time if they're not balanced properly through the BMS.

Worth considering a backup petrol generator or grid connection for top-ups if you're getting repeated outages. The Multiplus can handle AC in beautifully if needed.

Decent setup, @MarineGaz. Winter capacity's always the trade-off though—10kWh sounds healthy on paper, but it depends massively on your daily draw and how many consecutive grey days you're facing.

I'm running a smaller 5kWh bank on my boat and it's taught me that the real game-changer is load management, not just raw capacity. What's your typical winter consumption looking like? I found that dropping my heating load by switching to a more efficient system freed up way more headroom than adding another 5kWh would've.

Also curious about your Fogstar/Renogy mix—how are you finding the balancing? I've always stuck to matching cells from the same batch, bit paranoid about voltage drift across different chemistries. Probably overthinking it, but figured I'd ask since you've gone hybrid.

The Multiplus is definitely the sensible choice for this climate. Boring but effective, which honestly is exactly what you want when you're off-grid through January.

Solid choice on the Multiplus—though @MarineFrank's got a point about the ubiquity. That said, there's a reason everyone gravitates toward it: the inverter/charger integration and firmware updates are genuinely reliable.

Where I'd push back slightly on @LochSpirit's comment is that 10kWh through winter isn't necessarily cutting it fine if your generation strategy's complementary. I'm running 8kWh in my narrowboat setup with a Victron MPPT 250/100, and paired with a modest 2.5kW solar array angled for winter output, I rarely dip below 20% state of charge over December-January. The key's not the battery size alone—it's your generation-to-consumption ratio.

@BatteryRay's right that it depends on usage patterns, but also on backup. Are you running a generator? Mains feed-in? Shore power on the boat? That massively changes whether 10kWh is comfortable or hair-raising.

One thing worth monitoring: Fogstar and Renogy cells perform quite differently in cold weather. You

Winter's when those 10kWh start feeling more like 5kWh, mate—the cold doesn't do lithium any favours. Though I'll say, the Multiplus is genuinely bulletproof; I've had mine through three motorhome winters without a hiccup.

Real question is what you're running when the grid's down. If you're just keeping essentials alive (fridge, heating, lights), you're golden. But if you're expecting to run the kettle and hairdryer simultaneously, you'll be rationing power quicker than a pensioner on a fixed income.

Fogstar and Renogy mixed—that's a brave combo. They'll behave differently in cold, different charging profiles and all that. Works fine if you know what you're doing, but worth monitoring your cell voltages regularly so one bank doesn't start sulking.

The real trick through winter? A backup generator or two. Solar might give you 2-3 hours of useful charge on a decent day, rest of the time you're living off the battery. 10kWh sounds grand until you're three weeks into January.

Great thread, this. @MarineGaz, that's a solid foundation you've got there. The Multiplus is a workhorse—really reliable bit of kit.

What I'd add to what @RetiredNurse49's mentioned about winter capacity: have you got your battery bank somewhere insulated? Even a basic unheated shed with decent thermal mass makes a real difference compared to outdoor mounting. I've found a 5-10°C difference between inside and out can shift usable capacity noticeably, especially with lithium.

Also worth thinking about generator backup if you haven't already—not as a permanent solution, but for those genuinely grim weeks in January when you're getting three hours of daylight. Pairs nicely with a LiFePO4 system because you can charge efficiently without hammering the batteries.

How are you getting on with the mix of Fogstar and Renogy cells? I've been curious whether mixing brands causes any balancing headaches with your BMS.

Question for you @MarineGaz — how are you managing the battery temperature through winter? I've got a similar Fogstar setup and I'm wondering if thermal management's making the difference between your 10kWh staying usable versus what @RetiredNurse49's describing.

Are you keeping the batteries in an insulated box, or relying on the ambient temp where you've got them installed? I ask because I've been looking at some basic heating solutions — even a small 100W heater with a thermostat could keep things above 10°C, which seems to be where LiFePO4 really starts performing properly.

Also curious about your Multiplus settings — are you running it in any particular mode during prolonged outages, or just standard backup? The reason I ask is I've read a few posts suggesting the charging profile matters quite a bit when you're cycling heavily off stored power rather than grid-tied.

What's your typical daily draw during winter when solar's limited?

Spot on about the cold, @RetiredNurse49 — I've noticed the same thing on the boat. My 48V Fogstar bank basically hibernates when it drops below 5°C properly. The chemistry just doesn't cooperate.

@George1972, if you're asking about heating — I run a basic immersion heater on a timer tied to my Multiplus relay output. Kicks in if voltage creeps below a threshold. Costs a fair bit in winter consumption but keeps the cells functional. Alternative is wrapping the battery enclosure in insulation and accepting you're essentially running a smaller usable capacity December through March.

The real game-changer for me has been leaning harder on the diesel genset in winter rather than relying on the bank alone. Counterintuitive when you've got all that storage, but lithium in a UK narrowboat winter is genuinely temperamental. Charge cycles suffer, depth-of-discharge suddenly matters more, and you're burning auxiliary power just to keep things warm.

@MarineGaz's 10kWh is brilliant for autumn and spring, but yeah, winter strategy needs reth

Winter's the real test innit — my static caravan's 8kWh Fogstar setup drops about 30% capacity when it hits freezing, which is why I've got a cheap fan heater on a timer wired to kick in if the battery temp sensor says it's below 5°C (costs a tenner a month in solar but beats watching your usable capacity vanish).

The Multiplus handles it fine, but make sure you've got proper battery monitoring or you'll end up like @PennineNomad's boat — silent, cold, and very grumpy. Also worth noting that LiFePO4 doesn't like charging below 0°C, so if you're genuinely northern, a battery box with some thermal mass helps loads. I've seen people use old sleeping bags stuffed with bubble wrap, sounds daft but it actually works.

@George1972 — what's your ambient temperature actually hitting? That'll tell you if you need active heating or just insulation.

Mate, the winter capacity drop is brutal. I've got my tiny house setup on a south-facing slope which helps a bit, but even then my 10kWh's basically operating at about 70% of its summer performance come January.

The real trick I've found is thermal management — I've got a small 12V heating mat under my Fogstar cells (

Great setups everyone's sharing here. I'd add that the capacity hit during cold snaps is real, but there's a few tricks worth considering alongside what you've mentioned:

Thermal management makes a genuine difference — even a basic insulated box around the battery bank with a small 12V heating mat (thermostat-controlled) can preserve 10-15% of your usable capacity. Costs bugger all compared to oversizing your bank.

Also worth noting: discharge rates matter in winter. Cold batteries don't like being hammered hard. I've found that throttling my inverter's output slightly during freezing weather actually extends my runtime more than you'd expect, because the cells aren't fighting as hard against internal resistance.

@MarineGaz — 10kWh's a solid foundation. Have you got your panels tilted steeper for winter sun angle? Even a manual seasonal adjustment helps with the limited daylight we're working with.

The other thing nobody mentions much: keep a small petrol genset for those grotty 3-day grey spells in January. Your batteries will thank you for not running them flat repeatedly. Just saying