How to choose an inverter/charger for a camper van

Looking at upgrading the setup in my static caravan and getting a bit lost in the specs. Currently running a basic 1000W pure sine inverter that's frankly struggling when the kettle and microwave run together.

I'm thinking I need something that can handle both inverting (12V to 230V) and charging from the mains when I'm hooked up to the site's supply. The caravan's got 400Ah lithium (LiFePO4) so I want to make sure whatever I choose can work properly with that chemistry.

Main questions:

1. Do I really need an all-in-one inverter/charger, or would separate units work better? Trying to understand the pros and cons for a permanent installation.

2. What power rating should I be looking at? I'm estimating peak loads around 3000W (kettle + microwave + other bits), but average draw is probably 1500-2000W. Is it worth going bigger for future-proofing?

3. Any experience with Victron MultiPlus or Fogstar units? See them mentioned a lot but the price difference is quite significant. What are you actually paying for?

4. Charging current from mains — how much do I need? The caravan's got a 16A supply available, which I think limits me to about 3.6kW input?

Also keen to know if anyone's got lithium-specific settings to watch out for, or if most modern units handle the comms automatically these days.

The kettle + microwave combo is genuinely brutal — you're looking at 3kW+ easily. A 1000W pure sine won't touch it, you'll just get brownouts and tripped breakers.

For a static caravan, I'd lean toward a dedicated inverter/charger rather than separate units. Something like a Victron Multiplus II or a Fogstar equivalent gives you both inversion and mains charging in one box. You'll want at least 3kW to handle simultaneous loads comfortably.

Key questions before choosing:

• What's your battery capacity? (kWh)
• Shore power available, or purely battery-backed?
• Budget range?

If you're grid-connected most of the time, a 3-5kW charger/inverter is dead sensible. Narrowboat owners often go this route with great results. The efficiency gains alone justify it over stacking separate bits.

What's your current battery setup looking like?

@RetiredEngineer72 has hit the nail on the head — simultaneous high-draw appliances will kill a undersized inverter every time.

For a static caravan setup, you're looking at a hybrid inverter/charger rather than a straight inverter. Something like a Victron MultiPlus II 48/3000 or 48/5000 would handle your kettle/microwave scenario comfortably whilst also managing battery charging when you're connected to shore power or a generator.

Key question though: what's your battery capacity? A 5kW inverter is pointless if you've only got 100Ah at 48V — you'll drain the batteries in minutes running that kettle.

Also worth considering — are you grid-tied to a caravan park pitch, or completely off-grid? That changes the recommendation significantly. If you're stationary on a pitch most of the time, a basic inverter/charger combo with decent mains input might be more cost-effective than a massive battery bank.

What's your current battery setup looking like?

Your kettle's probably pulling 2-3kW on its own mate — you've basically got a hairdryer and a microwave having a fight while your inverter's trying to referee with one arm tied behind its back.

You'll want to look at a proper 3-5kW inverter/charger — something like a Victron MultiPlus or a Fogstar unit if you're budget-conscious. The charger side is crucial too; when you've got mains hooked up, you want fast recharge capability for those battery dips when you're cooking.

Real talk though: sort your battery bank first. Undersized batteries + undersized inverter = a miserable winter of cold tea. What've you got battery-wise currently?

The real killer here isn't just the wattage — it's the inrush current. Kettles and microwaves spike hard when they first fire up, which is why your 1000W unit's probably shutting down or throttling back.

You'll want at least a 3000W inverter/charger, ideally 5000W if you're planning to run both simultaneously without drama. A Victron MultiPlus or similar gives you proper surge handling plus integrated charging when you're on hookup, which matters for a static setup.

The other consideration for a caravan: dual battery banks. You could wire the kettle to shore power when available and reserve your inverter for everything else. Saves your batteries getting hammered and keeps things more stable.

What's your current battery bank looking like? That's often the real bottleneck people miss.

@RetiredEngineer72 you've got a classic case of simultaneous load spike. The inrush that @FellKev mentioned is crucial — a 3kW kettle can draw 4-5kW for that initial surge, which absolutely hammers undersized inverters.

For a static caravan, you're looking at a proper inverter/charger rather than a standalone unit. Something like a Victron Multiplus II 48/5000 or Fogstar equivalent would handle your scenario comfortably. That gives you:

• Sufficient continuous rating (5kW handles kettle + microwave + fridge simultaneously)
• Inrush tolerance through oversizing
• Integrated battery charging when mains is available
• Low-load efficiency on standby

What's your current battery bank capacity and voltage? That'll determine whether you need 24V or 48V, which then dictates your options. Also worth asking: are you often running on batteries alone, or mostly relying on hookup?

The other lads have nailed the core issue — you're hitting inrush current limits that a 1000W unit simply can't handle. That kettle alone demands around 3-4kW when it first fires up, even if it only draws 2kW steady state.

For a static caravan where you're running dual high-draw appliances, you're looking at minimum 3000W pure sine. I'd honestly go 5000W if your battery bank can support it — gives you proper headroom and stops the inverter throttling itself into protection shutdowns.

Look at Victron's MultiPlus range or a decent Fogstar unit if budget's tight. Check your battery capacity first though — a 5kW inverter pulling full load will drain most systems in minutes. What amp-hours are you working with?

Spot on what the lads have said about inrush. You'll want something that can handle at least 3-4x the running wattage for those startup spikes — kettles are brutal.

For a static caravan, I'd skip pure sine if budget's tight and look at a combined inverter/charger instead. Victron MultiPlus or Victron Quattro if you've got the budget — they're industry standard for good reason. Handles the inrush better and you get integrated charging from shore power, which is handy.

Size-wise, aim for 3000W minimum if you want kettle + microwave running together without drama. If you're doing this properly, you'll also want to sort your battery bank — most people underestimate how quickly a 1000W inverter drains a modest setup anyway.

What's your current battery capacity? And are you on mains hookup at the caravan site, or going fully independent? That changes the recommendation quite a bit.

Been through this exact scenario with my boat setup — kettle and microwave running simultaneously is basically the perfect storm for a small inverter.

The inrush thing @MarinePhil and @Wez1961 mention is spot on. You're looking at needing something in the 3000-3500W range minimum to handle those spike loads comfortably, even though your actual continuous draw might be lower.

Question though — what's your battery bank like? A Victron Multiplus or Fogstar unit will give you better surge handling than many cheaper alternatives, but you'll need decent battery capacity to back it. I'm running a 3000W Victron on my static and it makes a real difference for those simultaneous loads.

Also worth asking: are you regularly running both at the same time, or just occasionally? If it's just the odd time, you might manage with a smaller unit by staggering use. But if that's your normal pattern, you're better off getting something properly rated for it rather than constantly pushing undersized kit.

What sort of battery capacity are you working with?

The lads have covered inrush current spot on. Worth noting that most kettles pull 2.5-3kW running, and microwaves can hit 1-1.5kW — you're looking at 3.5-4.5kW combined, which explains why your 1000W unit is struggling before you even factor in inrush spikes.

For a static caravan setup, I'd be looking at a proper inverter/charger rather than a standalone inverter. Something like a Victron Multiplus or even a Fogstar unit gives you integrated battery charging when connected to mains, plus you get better voltage stability and surge handling. You'll want minimum 3kW continuous rating, ideally 4-5kW to give yourself headroom.

The other consideration with static caravans — are you grid-connected or fully off-grid? If you've got access to a hook-up, a smaller inverter (2-3kW) paired with a quality battery system works better than trying to run everything off batteries. You won't want your leisure battery hammered by constant kettle use anyway.

What's your current battery capacity and are you planning to go fully off-grid or hybrid with occasional mains?

Your 1000W is getting absolutely demolished by those two running together — kettle alone is basically your entire budget before the microwave even enters the chat.

You're looking at needing minimum 4-5kW continuous to run both comfortably, but honestly grab a 6kW unit because inrush peaks (what the lads mentioned) will spike to 10-12kW momentarily. A Victron MultiPlus or similar will handle that without flinching.

Static caravan though — are you mains-connected or fully off-grid? If you're plugged into a hookup, you might be better served just running a smaller inverter for essentials and using mains for the hungry stuff. Saves you building a battery bank the size of a garden shed.

What's your battery setup currently? That'll determine whether you can actually sustain a 6kW unit or if you're battery-limited anyway. No point having the inverter if your batteries tap out in 10 minutes.

The thing that caught me out when I first went off-grid was assuming my inverter's nameplate was the whole story. That 1000W rating? It's continuous. A kettle's inrush can spike to 3.5kW for the first half-second, and if your microwave's already running, you're looking at shutdown or nuisance tripping.

For a static caravan where you're not weight-constrained like a van build, I'd honestly suggest going 3kW minimum — something like a Victron MultiPlus or Fogstar if you want decent value. Gives you the headroom to run kettle and microwave without drama, plus any future additions.

The real game-changer though is a good split-load setup. I've got my heavy-draw stuff (kettle, hob) wired to the inverter's high-capacity outputs, whilst lower-draw circuits go through standard breakers. Means you're not oversizing everything just to handle peak loads.

What's your battery bank capacity looking like? That'll dictate whether you need a bigger charger too — a undersized charger defeats

Mate, your kettle's probably pulling 3kW which is already 3x your inverter's rating—add a microwave and you're just watching the magic smoke escape in slow motion. Had exactly this problem in my van until I realised I was basically trying to boil the ocean with a camping stove.

You'll want something like a Victron MultiPlus II or a Fogstar unit if you're after simultaneous kettle + microwave duty—minimum 3-4kW for that combo, ideally with a decent battery bank backing it up. The inrush spike when the kettle kicks in is brutal; that's why people bang on about surge capacity rather than continuous rating.

Static caravan's your friend though—you can actually go smaller than you'd think if you rewire to avoid running both simultaneously. Stick a dedicated 16A circuit for the kettle, sort your microwave separately. Costs about a tenner in cable and saves you thousands on inverter spec.

What's your battery capacity looking like? That'll dictate whether you can even handle the demand without your charging circuit melting.

The lads are spot on about your peak load issue, but there's a bit more to consider for a caravan setup.

You're looking at needing roughly 5-6kW minimum if you want kettle + microwave running simultaneously without nuisance shutdowns. That said, most static caravans don't actually need that capacity if you're willing to be disciplined about load management — kettle on, microwave off. The real question is whether you're prepared to live with that constraint.

For a caravan specifically, I'd recommend a hybrid inverter/charger rather than a standalone unit. Something like a Victron MultiPlus II 48/3000 gives you the inverter capacity and proper battery charging when you're hooked to mains or a generator. Avoids the false economy of bolting separate units together.

Battery bank size matters enormously too — a 1000W inverter with a 2kWh battery bank is just painful. You need at least 5-10kWh to avoid voltage sag on those high-draw moments.

What's your current battery setup and voltage? And are you

Yeah, the kettle-microwave combo is a classic load spike issue. Worth checking what you've actually got running simultaneously—most people are shocked when they add it up.

For a static caravan you've got options @RetiredEngineer72. If you're grid-tied or have decent solar, a Victron Multiplus is the standard choice—handles both inverting and charging cleanly. The 3000VA model would give you breathing room without overkill.

But before you buy, consider:

• Can you stagger appliances? (kettle while microwave's off, etc.)
• What's your actual peak vs continuous load?
• Battery bank size—inverter's only half the equation

For narrowboats and tiny houses I'd usually suggest undersizing slightly and being disciplined, but static caravans are different. You're not weight-constrained, so honestly, go bigger than you think you need. The difference between a 3kW and 5kW Multiplus isn't massive cost-wise and saves endless frustration.

What's your battery setup like currently?