Let’s talk batteries.
I know. Not the most romantic part of vanlife. But it’s the bit that decides whether your lights stay on, your kettle boils and your phone is charged when you’re parked up somewhere beautiful.
Get it right and you’ll never think about it. Get it wrong and you’ll think about it constantly.
So here’s the plain-English version.
Quick Answers:
The quick campervan leisure battery guide.
The best campervan leisure battery depends on your travel style:
- Lead Acid: Best for budget weekenders with basic power needs.
- AGM: Best for low maintenance and tight, sealed spaces.
- Lithium (LiFePO4): Best for full-timers, off-grid wild camping, heavy appliances, and saving payload weight.
| Feature | Lead Acid | AGM | Lithium (LiFePO4) |
| Typical Cost (UK) | £80 – £180 | £150 – £300+ | £170 – £550+ |
| Usable Capacity | ~50% | ~50% | ~80% – 100% |
| Weight (100Ah) | ~25 – 30kg< | ~25 – 30kg | ~11 – 13kg |
| Lifespan (Cycles) | 300 – 500 | 500 – 1,000 | 2,000 – 5,000+ |
| Best For | Budget / Weekenders | Mid-range / Sealed spaces | Full-timers / Heavy loads |
First, what is a leisure battery?
Your van’s starter battery has one job. Fire the engine, in a big burst, then step back.
A leisure battery (also called a habitation or domestic battery) does the opposite. It gives out a small amount of power for a long time. Lights, a fridge, a water pump, a phone charger.
That’s called deep cycle work. It needs a different kind of battery, built to be drained and recharged again and again. If you use a simple ‘starter battery’ for this, it’s a quick way to ruin it.
Two bits of jargon before we go on.
Amp-hours (Ah) is basically the size of your battery’s fuel tank. A 100Ah battery can, in theory, supply 10 amps for 10 hours.
The Depth of discharge, is how much of that tank you can use without harming the battery. Hold that thought, because it’s where the three types really differ.
Lead Acid Leisure Batteries: Pros, Cons & Cost
This is the traditional leisure battery. Lead plates in acid. The technology is well over a century old, and it still works.
It’s what I run. Two 130Ah batteries, wired together. My needs are modest. 12V lights, an occasional electric kettle, and charging phones and an iPad. For that, lead acid does the job nicely.
The good bits
It’s cheap. Ballpark, a decent 100 to 130Ah lead acid leisure battery costs somewhere around £100 to £180 in the UK. Cheapest to buy, by some distance. In fact, I bought my two for £85 each.
It’s also forgiving. It works with almost any basic charging setup, including the simple split charge systems fitted to many older vans. You don’t need to upgrade the wiring to use one.
Replacing one is easy too. Every battery shop knows what they are.
The not-so-good bits
Here’s the catch. You can only use about half the capacity.
Drain a lead acid battery much below 50% and you shorten its life. Often a lot. So my two 130Ah batteries give me 260Ah on the label, but only around 130Ah I can safely use.
They’re heavy as well. A single 100Ah lead acid battery can weigh around 25 to 30kg. Two of them? You’ll feel it when you lift them, and your van will feel it on the road.
Some types need topping up with distilled water. Some give off gas while charging, so they need ventilation. Sealed versions avoid the topping up, but the principle is the same.
And they hate sitting flat. Leave one discharged for weeks and the plates get coated in hard crystals. Sulphation, if you like the science bit. It permanently steals capacity.
A typical lifespan is a few hundred full cycles. Look after it and you’ll get a few years of weekend use.
Who is it right for?
Weekenders. Light users. Anyone on a tight budget, or with an older van. If your power needs are small, lead acid isn’t second best. It’s sensible.
AGM Leisure Batteries: Is the Upgrade Worth It?
AGM stands for Absorbent Glass Mat. Still lead acid chemistry, but the acid is soaked into glass fibre mats rather than sloshing about as liquid.
That small change makes a surprising difference.
The good bits
They’re sealed and spill-proof. No topping up. Very little gassing in normal use. That makes them safer to fit inside a van, and more flexible about where they sit.
They handle heavy loads better, too. If you plan to run an inverter for a kettle or a hairdryer, AGM copes with the sudden demand more happily than basic lead acid.
They also tend to charge faster, and they cope better with being cycled regularly. Lifespan is usually better than standard lead acid, often somewhere in the 500 to 1,000 cycle range if treated kindly.
The not-so-good bits
You still only get about 50% usable capacity. That surprises people. Pay more, and you still have the same rule.
They’re still heavy. Still lead.
And they cost more. Ballpark, anywhere from £150 up to £300 or more for a quality 100 to 125Ah unit, with premium brands at the top end.
Is that worth it? Well, it depends. If you’re considering AGM, ask yourself what you’re actually paying for. Sealed safety and tougher performance, yes. A dramatic jump in usable power? No.
Who is it right for?
People who want low maintenance and better performance without the price of lithium. Also anyone fitting a battery in a tight space, or inside the living area.
Lithium (LiFePO4) Campervan Batteries: Ultimate Power & Weight Savings
You’ll see this written as LiFePO4. It stands for lithium iron phosphate. You may also see “LiPo4” online. That’s a common mix-up, and it’s a different thing. LiFePO4 is the one you want for a van, and it’s much more stable than the lithium in a phone.
This is the premium option. And it earns the title.
The good bits
Usable capacity is the big one. You can use around 80 to 100% of a lithium battery. A 100Ah lithium gives you roughly twice the usable power of a 100Ah lead acid.
So let’s do the sums. My pair of 130Ah lead acid batteries gives me about 130Ah usable. A single 130Ah lithium would give me about the same. One battery instead of two.
It’s also light. Often a third to a half the weight of lead acid. A 100Ah lithium might weigh 11 to 13kg. In a van where every kilo of payload counts, that’s huge.
Lifespan is where it really shines. Good LiFePO4 batteries are often rated for 2,000 to 5,000 charge cycles. That could mean ten years or more.
They charge quickly and hold their voltage steady until nearly empty. So your lights don’t slowly dim as the battery drains. Everything runs normally, right until it doesn’t.
There’s a built-in brain too, called a BMS (battery management system). It protects the cells from overcharging, over-draining and overheating.
The not-so-good bits
Price. Ballpark, budget 100Ah lithium batteries now start around £170 to £250. Quality brands with smart features and good support can run to £400 to £550 or more. That’s a lot more than lead acid up front.
Over many years it can work out cheaper per use. But that only helps if you’ll actually keep it that long.
Then there’s the charging question. Lithium needs the right charging profile. An old charger, or a basic split charge relay, may not suit it. Many vans with modern “smart” alternators need a DC-DC charger to feed lithium properly. That’s an extra bit of kit, and extra cost.
And the cold. This one matters in the UK.
Lithium can be discharged in cold weather. But charging it below freezing can permanently damage the cells. Good batteries have low-temperature protection, which simply stops charging when it’s too cold. Some have built-in heaters. Cheap ones may not.
So if you van through winter, check this before you buy. A frosty Scottish morning with a battery that won’t charge isn’t fun.
One more oddity. Lithium voltage stays flat for most of its range. So you can’t judge how full it is by voltage alone, the way you can with lead acid. A battery monitor is a good idea.
Who is it right for?
Full-timers. Remote workers. Anyone with a fridge, laptop, induction hob or lots of kit. Also anyone short on space or payload, or planning to keep their van for years.
Charging: the part everyone forgets
A battery is only half the story. The other half is how you fill it.
In a campervan, there are usually four ways.
Driving. The alternator charges the leisure battery while you drive, through a split charge relay or a DC-DC charger. Relays are fine for lead acid. Lithium really wants a DC-DC charger.
Solar. Panels on the roof feed a controller, which feeds the battery. Great for weekends away. The controller must be set to the right battery type, or it will under or over charge.
Mains hook-up. A plug-in charger on a campsite. Again, it needs to match your battery.
Time. Lead acid batteries charge slowly in their final stretch. Often hours. Lithium zips through it. If you do short drives, that matters.
The golden rule is simple. Match the charger to the battery. Switching to lithium without checking the charging system is the classic beginner mistake.
Cold weather, quickly
Lead acid and AGM lose some usable power when it’s cold. A battery at 0°C gives you less than the same battery at 20°C. A fully charged one is fine. A flat one can even freeze.
Lithium, as above, won’t charge when frozen unless it’s protected.
For most UK weekenders, neither is a disaster. Just know your battery’s limits.
So which should you buy?
Ask yourself three questions.
What are you powering? A few lights and a phone charger is very different from a fridge, laptop and diesel heater fan running daily.
How often are you out? Weekends and holidays, or most of the year?
What’s your budget, today and over time? Cheap now, or cheaper later?
Here’s my honest take.
If you’re new, camping occasionally and running light loads, lead acid is a great place to start. It’s what I use, and it suits how I travel. Don’t let anyone shame you into spending hundreds you don’t need to.
If you want low maintenance and tougher performance, AGM is a solid middle ground.
If you live in your van, or you’re power hungry, lithium is the clear winner. The cost stings. But the weight saving, the usable capacity and the lifespan are hard to argue with.
A quick recap
Lead acid. Cheapest. Heavy. About 50% usable. Simple to charge. Great for light, occasional use.
AGM. Mid price. Sealed and tidy. Still about 50% usable. Handles loads better. A good all-rounder.
LiFePO4. Most expensive. Light. 80 to 100% usable. Very long life. Needs proper charging and cold-weather care.
None of them is wrong. They’re just different tools for different trips.
So the real question isn’t “what’s the best battery?” It’s “what’s the best battery for the way I travel?”
Answer that honestly, and you’ll choose well.
Got questions about your own setup? Leave a comment. I’m happy to help if I can.
