How to choose an inverter/charger for a camper van

The real issue here is that kettles and microwaves are basically the worst-case scenario for battery-based systems—they're peak demons. You need to think about this differently.

For a static caravan, you've got options the van lot don't: you can actually use shore power properly. If you've got a mains hook-up on site, invest in a decent inverter/charger (Victron's the gold standard, but Studer or even Growatt work) rather than just a standalone inverter. This way your batteries stay topped up when you're connected, and the charger handles mains input intelligently.

If you want to run kettle + microwave simultaneously off batteries, you're realistically looking at 4-5kW minimum—plus your battery bank needs to be sized accordingly. That's a proper investment for a static setup though.

What's your actual battery capacity at the moment? And are you permanently hooked up to mains, or is this for off-grid stretches? The answer to that changes everything about which direction to go. A Victron Multiplus II 48/3000 is overk

Ah, the classic "let's boil the kettle and nuke yesterday's curry at the same time" problem. Been there, mate.

Thing is, @RetiredEngineer72, a 1000W inverter is basically a chocolate teapot when you've got simultaneous high-draw appliances. Kettles alone pull 2-3kW

You'll need to size for that peak load, not average. Kettle alone is what, 2-3kW? Add the microwave and you're easily looking at 4-5kW combined. Your 1000W inverter doesn't stand a chance.

For a static caravan, I'd honestly suggest either going larger (3kW+ inverter/charger) or just accepting you can't run both simultaneously. We went with a Victron Multiplus 3000 in our setup and it's been solid—handles the peaks without faffing about.

Factor in your battery bank too though. Even with a beefy inverter, if you're drawing 4kW from a small battery, you'll crater the voltage. We've got 10kWh usable and it makes a real difference.

What's your current battery capacity? That'll determine whether a bigger inverter actually helps or if you need to tackle the battery side first.

The harsh reality is you can't really have it both ways with batteries. A 1000W inverter simply won't handle simultaneous kettle + microwave—you're looking at 3-4kW peak there, maybe more.

For a static caravan, I'd seriously consider whether you need to go full inverter or if you could hardwire the heavy loads (kettle, cooker, immersion heater) to mains when you're connected to hook-up. That's what most of us do on narrowboats.

If you want true independence, you're looking at a 3-5kW inverter/charger like a Victron MultiPlus or Fogstar unit, plus a battery bank to match. But that gets expensive and space-hungry fast.

What's your actual power source? If you're mostly on a site, grid connection with solar topping things up might be more practical than trying to run everything from batteries. The maths rarely work out for high-draw appliances unless you've got the budget for serious kit.

What size battery bank are you running currently?

You're looking at simultaneous kettle + microwave, which is genuinely difficult without either upsizing your battery bank massively or accepting you can't run both together. @Harry1965's right about sizing for peak load.

For a static caravan (I'm assuming mains-connected some of the time?), a 3-5kW inverter/charger makes more sense than upgrading just the inverter. Something like a Victron MultiPlus II 48/5000 gives you the inverter capacity you need and a proper charger to top up from shore power. You'll still need decent battery capacity though — the kettle's the real killer at 2.5-3kW for several minutes.

What's your current battery setup? If you're on a small LiFePO₄ bank, even a 5kW inverter will sag under load. If you've got decent capacity (say 10kWh+), a larger inverter becomes practical.

Alternatively, accept the limitation and just don't boil the kettle and microwave simultaneously — most caravanners I know have made peace with this. A small 2kW inverter/charger unit is often more than sufficient for realistic usage patterns.

What battery size are you working with?

Right, so @Harry1965 and the others have nailed the peak load issue. Rather than just throwing a massive inverter at it, worth asking—do you actually need kettle and microwave running simultaneously?

Most caravans manage fine by staggering use. Boil the kettle, wait 2 mins, then microwave. Bit of planning beats spending £2k on a 5kW system you'll rarely max out.

That said, if you're set on simultaneous load, you're looking at 3.5–4kW minimum inverter. A Victron Multiplus 48/3000 is solid and handles mains charging decently too. Or if you've got the space and budget, step up to a 5kW unit—they're not that much dearer these days.

What's your current battery capacity? And is this a permanent install (mains hookup likely) or fully off-grid? That changes the calculus quite a bit.

Mate, simultaneous kettle and microwave is basically the killer combo. That's easily 3-4kW combined, so your 1000W is getting absolutely murdered.

Worth asking yourself first: do you actually need both running at the same time? In my tiny house setup I staggered it — kettle while the microwave's off, saves me a fortune in battery capacity. If you genuinely need simultaneous loads though, you're looking at a proper dual-input unit.

For a static caravan I'd suggest looking at a Victron MultiPlus rather than a dedicated inverter. Yes, pricier upfront, but it manages the battery charging intelligently and handles surge loads better. Alternatively a Fogstar or Renogy combo if budget's tight.

Real talk though — before you upgrade, calculate your actual peak demand. If it's genuinely 4kW+ simultaneous, you'll need batteries to match, and that gets expensive fast. Might be smarter to use a portable kettle on mains when you're connected to hookup.

What's your current battery capacity?

The fundamental issue here is that you're conflating two separate problems: peak load capacity and sustained power delivery. Your 1000W unit simply can't handle the inrush current when both heating elements fire simultaneously—kettles alone can pull 2.5-3kW, and microwaves another 1.2-1.5kW.

Rather than just upgrading the inverter wattage, you need to think about this holistically. A 3-5kW pure sine unit (Victron Multiplus II or similar) would handle the peak, but you'll also need battery capacity to sustain it. A 48V LiFePO₄ setup with at least 5kWh usable gives you the headroom without constantly hammering your batteries.

The other option worth considering: stagger your high-draw appliances. Most caravans manage fine with sequential use rather than simultaneous. If that's genuinely not workable for your lifestyle, then yes, you're looking at a proper upgrade path—inverter, battery bank, and potentially solar expansion.

What's your current battery capacity, and are you looking at grid-connected or

Curious about your battery bank size though—that's half the battle, isn't it? A 3-4kW simultaneous load needs not just a beefy inverter but proper battery capacity to deliver it. What's your current setup there? And are you thinking of going with something like a Victron MultiPlus, or exploring the newer all-in-one units?

@RetiredEngineer72 sounds like you need a proper inverter/charger combo rather than a standalone inverter. What's your battery bank capacity? That's the real constraint—I'd say minimum 10kWh for hassle-free kettle+microwave duty. A Victron MultiPlus 3000 or similar gives you the grunt plus integrated charging when you're on hookup.

Static caravan = perfect use case for a Victron Multiplus II 3000. Kettle and microwave together will happily obliterate a 1kW unit, but a proper inverter/charger combo lets you pull from mains when available and won't leave you sweating during peak loads. What's your battery capacity looking like though, as @MuddySkipper rightly pointed out?

Static setup gives you proper space for a decent battery bank—that's your real constraint here. Before jumping to a 3kW unit, sort your batteries first. What capacity you running currently? A Multiplus II is solid but they're not cheap. Could stretch to it if your DC side can handle it, but no point without the amp-hours to back it up.

Static caravans are brilliant for this. You'll want to size your battery bank properly first—a 3kW inverter won't help much if you're draining a small bank too fast. What capacity are you running now? Also check if you've got space for additional lithium alongside existing batteries. Victron's planning tool sorts this out nicely.