Zeliox Neo 4000 vs Clayton Power vs Victron: all-in-one or modular?

Ask someone which leisure battery to put in a campervan and you'll get a brand name. Ask which power system, and you've asked a much bigger question: do you want one clever box that does everything, or a set of parts you bolt together into exactly the system you want?

That's the real divide here. The Zeliox Neo 4000 and the Clayton Power LPS II are all-in-one units, with the battery, the inverter, the chargers and the brains in a single case. Victron is the opposite philosophy: a kit of separate components you design into a system. None of the three is simply "best." They're answers to different questions, and the trick is knowing which question is yours.

You'll find all three out in the wild. Converters like Taylored fit a Clayton in their smaller Offtrail, offer the Zeliox as an upgrade, and build their big Offtrax around Victron. Even one workshop picks by the job, which tells you something.

The real divide: one box, or a system

An all-in-one puts the lithium battery, the inverter that turns 12V into mains, the chargers (solar, alternator and hook-up) and the monitoring into a single sealed case. You mount it, connect a handful of cables, and you're done. Neat, quick, and one company to call.

Victron does none of that in one box. You choose an inverter-charger, a solar controller, a DC-DC charger, a battery monitor, maybe a central display, and a battery, and you wire them together. It's more work and more wires, but you've built exactly the system you wanted, and you can change any part of it later.

Hold that distinction in your head, because install time, repairs, expandability and cost all flow from it.

At a glance

Clayton Power LPS II: the neat all-rounder

Clayton Power is a Danish firm whose LPS II units are the established name in van all-in-ones. The popular LPS II 3000 packs around 2kWh of lithium (160Ah), a 2,300W pure-sine inverter, a 400W solar controller, alternator charging (500W, or 1,000W with their Super Charger upgrade) and hook-up charging into a case weighing just 27.5kg. It talks to the Clayton GO app over Bluetooth. UK price is around £3,250 plus VAT.

What's to like: it's genuinely light, genuinely simple, and proven. Installers rate it for "no complicated wiring," and that low weight matters on a van where payload is precious.

Two honest catches. First, a buyer-beware on the names: the model number is roughly the inverter's wattage, not the battery's capacity. The "3000" holds about 2kWh, the "2500" about 1kWh. Don't read the number as kilowatt-hours, because even Clayton's own marketing and detailed spec pages don't agree with each other (the headline peak-power claims vary wildly page to page), so judge it on the steady ~2,300W continuous output, not a flattering surge figure. Second, and it's the structural weakness of any all-in-one: if the box fails out of warranty, you've lost the lot, and owners report a replacement runs around £3,500 plus fitting, with some dealers reluctant to repair a sealed unit. The base warranty is 24 months.

Zeliox Neo 4000: the powerhouse

The Zeliox Neo 4000, now under Eberspächer, is the muscular newcomer. It's also all-in-one, but built around a 48V core rather than 12V, which is how it delivers a 4,000W continuous inverter (8,000W peak), the most power here by a clear margin. It starts at 2.4kWh of storage and expands to a hefty 9.6kWh with extra modules, takes up to 1,440W of solar and fast 120A alternator charging, has a 4.3-inch colour display, and an app with both Bluetooth and 4G so you can check the van from your sofa. Warranty runs up to five years with registration. Reckon on about £3,700 for the unit, or around £4,250 fitted.

It's the pick if you want serious power and big, expandable storage from a single tidy box, with the slickest monitoring of the three. The caveats are fair: it's the newest product here, so there's little long-term reliability history to lean on; it's the priciest; stock has been patchy; and the same single-box risk applies as with the Clayton. A couple of the finer figures (pure-sine confirmation, the exact mains-charging wattage) are quoted by retailers but not nailed down on Eberspächer's own spec sheet, so confirm them before you commit.

Victron: the system you build

Victron isn't a product, it's an ecosystem, and it's the one serious van builders reach for by default. A typical setup combines a MultiPlus inverter-charger (or a Phoenix inverter if you don't need hook-up charging built in), a SmartSolar MPPT for the panels, an Orion-Tr DC-DC charger for alternator top-ups, a SmartShunt to measure the battery properly, and often a Cerbo GX brain with a small touchscreen. Every smart part has its own Bluetooth and is set up through one app, VictronConnect, and if you add a GX device you get VRM, a genuinely good free cloud-monitoring portal with alarms and solar forecasting. It's the system that lets you sit in a pub garden and check, on your phone, that the roof has quietly put back everything last night's telly and fridge took out.

Crucially, you're not locked to Victron batteries. Plenty of UK builds pair Victron electronics with a third-party lithium like a Fogstar or a Roamer, which is often where the value lives.

The upsides are the flip side of the all-in-ones' weakness. If anything fails, you swap that one part and the rest keeps running, and you can buy replacements from dozens of suppliers. You can add solar, add a battery, or grow the inverter later. On parts alone it's often cheaper, too: a solid mid-van Victron core lands somewhere around £1,000 to £2,600 in components, depending on battery size.

The cost is effort. You have to design it, wire it, and configure it, and unless you're confident that means paying an installer, who may need a couple of days to do it properly. It's the most capable and most flexible system here, and the most work to get running.

Convenience now, or fixability later

Strip away the spec sheets and this is the real decision.

The all-in-ones are lovely. One box, a few cables, a tidy install, one app, one warranty. For a lot of people that's exactly right, and the Clayton in particular has made van electrics accessible to people who'd never wire a busbar in their life. But you're trusting everything to a single sealed unit. The 3am version of that risk is the one to picture: a flat battery, no hook-up within reach, and a fault you can't split into a cheap part, because the cheap part is the whole £3,000-odd box.

Victron asks more of you up front and pays you back later. It's fiddlier to build and easier to get wrong, but a Victron system can be nursed, repaired and upgraded piece by piece for a decade, and even sold off in parts if you ever break the van. If you keep your vans a long time, that adds up.

What it gets you over a weekend

Numbers are easier with a real example. A typical off-grid weekend for two, fridge ticking over, lights, phones and a laptop charging, a few induction-hob brews and a bit of telly, lands somewhere around a kilowatt-hour a day, more if you cook properly on the hob.

• The Clayton 2500 (around 1kWh usable, despite the name) is a day, maybe two, before it wants sun or a shore line. Fine for weekends with a decent solar top-up.
• The Zeliox Neo 4000 starts at 2.4kWh and climbs to 9.6kWh with extra modules, so it'll see most people through a long, hook-up-free week.
• A Victron system is whatever you build it to be: pair the electronics with a big third-party lithium (a 460Ah Fogstar or Roamer is popular) and you're in the same multi-day league, with room to add more later.

The lesson isn't that bigger is always better. It's that you should size the system to how you actually camp, not to the headline number on the box.

So which should you choose?

• Choose the Clayton Power LPS II if you want the simplest, lightest, most proven all-in-one, your power needs are modest to middling, and you value a tidy, DIY-friendly install over outright wattage. It's the easy, sensible default for a smaller camper.
• Choose the Zeliox Neo 4000 if you want the most power and the biggest expandable storage in one box, with the best monitoring and the longest single-unit warranty, and you're comfortable being an early adopter of a pricier, newer product.
• Choose Victron if you want maximum flexibility, expandability and repairability, the freedom to pick your own battery, and a system you can own and evolve for years, and you've either got the skills or will pay a good installer to set it up.

There's no shame in any of these. The worst choice is the one that doesn't match how you actually use the van.

Before you buy: check the numbers

One very Campervan.win point to finish on. Verify the figures against the manufacturers before you spend, because this category is full of slippery specs: model numbers that aren't capacities, peak-power claims that change from page to page, and prices and stock that move fast. The numbers above are accurate as we write, but a five-minute check of the current spec sheet is always worth it on a four-figure purchase.