How to Choose the Best Campervan Batteries

Graham Bogie

Choosing the best campervan batteries can be a bit of a minefield. There’s no one size fits all answer. What suits one person may not suit another.

Understanding the types of batteries available, the capacity you need for your van lifestyle, the relative cost and how to take care of them will help when it comes to choosing the best campervan batteries for you.

The camper van electrical system is one of the most important parts of any camper van conversion. 

Get it right and you’ll have enough energy to power your lights, fridge, heater, camper shower and charge your laptops and camera batteries.

Get it wrong and at worst, you’ll be in the dark.

Having the perfect camper solar panels fitted, a B-2-B charger and a hook up facility is only half the job though. 

Without the right battery bank to store all that free energy, you run the risk of falling short and sipping on warm beers in the dark.

To help you wade through the detail and fit the best camper battery for your needs, here’s all you need to know.

This post is part of our series on campervan electrical components.

If you’re new to electrics or van builds, take a look at our starter guide to campervan electrics first.

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Understanding campervan batteries

The first thing in choosing the right batteries is understanding the different types of camper batteries.

Starter batteries

With a flat battery, your car or camper won’t start.

The engine needs a starter battery to supply energy to the starter motor which in turn cranks the engine.

The starter motor needs a big jolt of energy to get going though, rather than a trickle.

Starter batteries are designed to provide a big burst of energy, fast and use as much as 20% of their total capacity per start.

Once the engine starts up, the alternator recharges the starter battery so it’s primed for the next time you start it up.

While you need a starter battery for the engine, these are not the right type of batteries to run your campervan accessories, appliances and lights.

a campervan parked beneath trees

Deep cycle / leisure batteries

Deep cycle batteries are often referred to as 12v leisure batteries.

Unlike starter batteries, a deep cycle battery is designed to release energy in a steady flow over a longer period. 

They can discharge a lot of their energy in a longer, deeper energy drain, something that would kill a starter battery in quick time.

Deep cycle batteries can withstand hundreds, if not thousands of discharges and recharging cycles, making them ideal for storing energy for your camper van electrical needs.

Types of camper batteries

Battery technology has been evolving for hundreds of years to the point we can now stream movies on our smartphones, powered by ultra thin lithium batteries.

Van lifers can benefit from these advancements in technology too. 

There are 4 types of leisure battery on the market:

  • Flooded lead acid (FLA)
  • Gel batteries
  • Absorbed glass mat (AGM) batteries
  • Lithium-ion batteries

Each uses slightly different chemistry so the way they work and perform is different too. 

Flooded lead acid (FLA)

Flooded lead acid batteries are the oldest technology battery on the list.

A combination of lead and sulphuric acid generates a chemical reaction to provide electricity. 

The battery container contains liquid acid. The charging process creates hydrogen and oxygen gases which are released through vents. 

With prolonged use, the acid evaporates so regular maintenance is needed to keep them topped up.


  • Low initial outlay cost
  • Largest range of physical sizes of all leisure battery types
  • Resilient to occasional over charging
  • Proven old technology 
  • Lifespan can be 4-8 years with regular maintenance and careful charging


  • Performance begins to degrade over time so the battery won’t hold a charge as well
  • Battery life significantly reduced if drained by more than 50%
  • Under some circumstances such as over charging they can emit a sulphuric gas, a smelly and potentially dangerous situation
  • The release of hydrogen can be rather dangerous. At worst, if the gas is ignited, the battery could explode so they must be ventilated well
  • Needs regular maintenance
  • Must be stored dry when not used for long periods

Until relatively recently, flooded lead acid batteries were considered high tech batteries for campervans.

They’ve since been superseded by gel, AGM and lithium-ion batteries.

Given the list of disadvantages compared to the alternatives below, we don’t recommend using flooded lead acid batteries.

Gel cell batteries

Gel cell batteries are also referred to as gel batteries.

They work in a similar way to flooded lead acid batteries, except they use a gel instead of liquid, giving far better advantages.


  • Maintenance free
  • Don’t give off any gases so doesn’t need ventilation
  • Have a longer shelf life than FLA
  • They are sealed so won’t leak if installed sideways
  • Operate better in warmer and colder climates than AGMs
  • Can be stored for long periods without use so ideal for seasonal use


  • Battery life significantly reduced if drained by more than 80%
  • Performance remains efficient until it reaches the end of its life
  • More expensive initial outlay than traditional flooded lead acid and AGM deep cycle batteries.

When we upgraded our solar panels in Patagonia in 2019 we upgraded to gel cells batteries and have been pleased with their operation to date.

AGM deep cycle batteries

AGM batteries were developed in the 1980s for military use and became the standard for auto manufacturers and campervans. 

They work in a similar way to flooded lead acid batteries, except they use electrolyte soaked glass fibres.

The benefit is these batteries are dry, sealed and don’t need a vent. So unless the casing is significantly damaged there’s no risk of gases even when upside down.


  • Maintenance free
  • About 20% smaller physically in weight and dimensions than an equivalent gel battery
  • Have a longer shelf life than FLA
  • Can be stored for long periods without use so ideal for seasonal use
  • Can be installed sideways


  • Battery life significantly reduced if drained by more than 80%
  • Performance remains efficient until it reaches the end of its life
  • More expensive initial outlay than traditional flooded cell acid
  • Performance in cold climates is worse than FLA batteries

Lithium LiFePO4 / Lithium-ion / Li-ion

Today, lithium-ion batteries are at the top end of battery technology.

While they’ve been around for a while, prices have fallen as popularity has grown, making them far more affordable than when we converted our Sprinter van.


  • 30% smaller in size and weight to equivalent AGMs
  • They deliver over 90% of their capacity so you can buy much less amp hours
  • Can be installed sideways
  • Charge more quickly
  • Long life


  • Can’t charge in temperatures below 0°c so you’ll need to control the temperature in their operating position
  • Higher initial outlay cost (double expense if they fail early)
  • At this time, finding lithium-ion batteries in some parts of the world is quite difficult
  • A battery management system is needed to protect the lithium-ion battery bank from excessive discharging, over charging and to control the load and charging of each cell. Some batteries have this included within them though
  • Needs to be stored at a 40% charge so needs monitoring while in storage
  • If a lithium battery is discharged to zero, you’ll need a special charger to “unlock” it
  • Some battery monitoring maybe essential such as battery temperature sensors

So in summary:

  • Cheapest upfront costs are Flooded lead acid batteries
  • Most efficient batteries are lithium-ion
  • Most dangerous are flooded lead acid batteries
  • Least recommended (by us) flooded lead acid batteries
  • Highest upfront costs are lithium-ion
  • Easiest to install are AGMs and gel batteries
  • Best campervan batteries for seasonal use are AGM and gels
  • Until lithium-ion prices fall, gels are a better option for us and our needs today.

But choosing the best campervan batteries isn’t only about the upfront costs and installation.

It’s important to understand what capacity you need, the lifespan of the batteries and running costs too.

These factors are dependant upon how the batteries are used so we’ll look at each of these now.

How much electric do you need in your camper van?

Close up of a lightbulb with bokeh light effects in the background

Batteries are measured in amp hours, so before deciding which 12 volt deep cycle leisure battery you need, calculate how much energy you’ll use in your campervan. 

Battery efficiency

Batteries aren’t 100% efficient so don’t deliver 100% of their amp hours. 

Flooded lead acid batteries are around 50% efficient. Gel and AGM batteries fair better at around 80% efficiency.

Litium-ion are super efficient and can provide more than 90% of their stored energy so saving on space and weight. 

While the battery may provide a certain amount of energy, the electricity needs to travel along cables, through junctions and switches to the appliances.

These circuits are inherently inefficient too so we need to make some allowance for further losses. 

Does all this sound a bit too complicated? Fortunately, we’d made the whole process simple for you with our solar battery bank calculator.

voltage reading on old fashioned device

For accuracy, use our Solar Battery Bank Calculator.

Charging campervan batteries

Batteries laid out in a triangle formation seen from above

To meet your energy needs, those batteries need to be fully charged every day too.

Our article on campervan electrics goes into more detail on how to charge leisure batteries. We set out the key points here to summarise.

Needless to say, to meet all your daily energy needs, the batteries need to be recharged.

This is why you need to consider your expected lifestyle. Living in a van isn’t the same for everyone.

Some van lifers will spend most of their time on campsites where hook up is available. Charging the camper’s batteries each day isn’t a problem.

Others prefer to boondock in their van, wild camping with no facilities. Charging your camper batteries while living off grid depend on running the engine and solar energy.

Consider the likelihood of keeping the batteries topped up every day and if necessary, install additional battery capacity to allow for off grid living.

Leisure battery lifespan and cycles

campervan living off grid in a forest

Manufacturers provide an indication of expected lifespan of their batteries in years and in cycles.

They can’t predict how everyone will use their batteries so it’s relatively vague and often a wide range.

We break it down here as best we can.

Battery lifespan in years

The average lifespan of each type of campervan battery is:

  • Flooded lead acid | 4 – 8 years with regular maintenance
  • AGMs | 4-7 years
  • Gel batteries | 2-4 years some are upto 15 years if used moderately
  • Lithium-ion | 7 – 21 years (though not tested in campervans for this length of time)

These vary according to manufacturer and battery so check specifications before you buy.

Battery cycles

Batteries also have a lifespan based on how many times they are discharged to a specified depth of discharge or DoD. This is called a charge cycle.  

In a controlled environment, manufacturers test batteries to give an indication of their performance.

1 battery cycle is defined as using 100% of the battery.

So for example if you use 30% of the battery one day and it is recharged to 100%, then use 50% the next day, then 20% on the third day, you’ll have used and replaced 100% of the battery charge. Or 1 battery cycle over 3 days. 

With charging from multiple sources you can see how it’s difficult to measure how many cycles used. 

Again, expected cycles from a battery vary by manufacturer but also by how heavily they’re used.

Usage is considered heavy where the full capacity of the battery is used every day. For example, if you install just enough battery capacity to meet your needs and keep it charged.

Usage is considered low where the full capacity of the battery is used every couple of days or so. For example if you install twice as much battery capacity to meet your needs and keep it charged.

Generally speaking, you can expect a greater number of cycles from lower usage.

Choosing campervan batteries based on cost

electricity power station

Batteries can carry a hefty upfront price tag so it’s tempting to choose a battery type that doesn’t demand a high cash outlay.

It’s a valid approach if access to funds during your van conversion is tight. 

We suggest you at least consider the big picture before you finalise your decision though.

So how can you compare batteries based on cost? 

Use our free Battery Life Calculator.

For this one, you need the spec of each battery – the lifespan and cycles specified by the manufacturer.

If they’re provided a range for these figures, take your pick depending on how cautious you feel.

In summary

Close up of auto battery

The lifespan of lithium-ion batteries is so long its hard to feel completely confident in it. Especially given they haven’t been around that long yet.

Suffice to say though, you’re unlikely to need to replace them for a long time unless there is a catastrophic failure.

The battery comparison calculator assesses your energy use against the size of the battery bank and the manufacturer’s specification.

It assumes the replacement costs will be the same as the cost of the batteries you’ve entered. Of course, better technology will continue to advance and the cost of like for like replacements will probably fall, but you can get the picture.

Play around with the numbers too.

Installing more battery power may actually make the overall cost fall.

We’ve calculated the cost and the number of times you can reasonably expect to replace the batteries in the compared period.

This may affect which batteries you choose, depending on where you plan to travel and how accessible replacement batteries are.

What campervan battery setup is best for you?

red campervandriving through a wintery mountain scene

So armed with all this new found knowledge, how do we bring it all together to choose the best campervan battery for you?

There’s several factors to consider when choosing the best campervan batteries for your conversion.

Your decision will be based on personal preference as well as your lifestyle and the pros and cons of each of type of battery.

In attempt to help, we’ve tried to summarise what we think here.

  • Based on cost alone, gel cell batteries win for anyone living in a van for more than a couple of years.
  • If you think your batteries will be positioned in a location where temperatures could fall below 0°c, gel batteries are the way to go. They’re the only ones that will charge in sub zero conditions.
  • If you plan to own the van for less than 2 years, or if your conversion budget is being squeezed, AGMs are a good choice because the upfront cost is so low.
  • If you plan to travel to remote locations and developing countries where choice may be limited, consider avoiding lithium-ion batteries. They have been known to fail, leaving you stranded without replacements. AGMs and gel batteries are more widely available.
  • If saving space and weight is critical in your build, lithium-ion batteries are the best choice but make sure you locate them somewhere warm if you plan on travelling in extreme temperatures.
  • Best battery for off grid living is probably the lithium battery. You can install more batteries for the same capacity and less weight so allowing for longer period off grid. If you can afford it!

Monitoring your batteries

monitoring battery level on a phone

A key aspect of life in a van revolves around the health of the batteries providing all the power for lights, camera batteries, fridge and any campervan appliances installed.

Useful information includes:

  • Battery capacity
  • How full the charge is
  • Temperature of batteries
  • Confirming they are charging
  • Identify when there is a problem
  • How much charge is coming from the:
    • solar panels
    • alternator
  • What is the usage level?
  • Making sure your batteries wired in parallel remain balanced
  • And more

There are many dedicated battery monitors on the market. Some carry pretty hefty price tags.

Or you can get some of the information from your solar panel controller and battery chargers. 

A simple volt meter fitted correctly provides a reasonable indication of your battery level too.

Switching to lithium-ion batteries

If you want to install lithium batteries but can’t afford the upfront cost yet, you can change them at a later date.

Make sure the solar charge controller and battery to battery charger you install now are compatible with lithium batteries too so you don’t have to replace these expensive parts later.

Check the battery sizes too. Aim to buy batteries the same physical size as the lithium batteries you’d like to swap to so you don’t have to reconfigure the housing.

For vehicle models with smart charging alternators, investigate what management components you need to charge a lithium-ion battery. 

Some may need a battery to battery charger as opposed to a split charge relay.

Campervan battery installation

You many need to purchase several batteries to achieve the amp hour capacity you need.

For example, if you need a 300ah battery bank, you could buy 2 x 150ah or 3 x 100ah batteries.

We’ve heard some people say to avoid wiring in parallel but we don’t agree.

The aim of wiring your batteries together in parallel is to enlarge your capacity without installing batteries the size of a coffin.

Make sure all batteries in the bank are identical sizes and from the same manufacturer.

What you do need to take care of is balancing. All the batteries in the bank should charge and discharge equally to minimise efficiency losses.

Here’s a diagram of how we’ve wired our 2 x 115ah gel batteries in parallel. 

campervan batteries parallel wiring diagram

There are other ways of wiring the batteries in parallel but they’ll be less efficient so should be avoided.

Here’s the wiring diagram for battery banks with more than 2 batteries wired in parallel.

3 campervan batteries parallel wiring diagram

You could wire the batteries in series too if you need a 24v system, but check with the manufacturer first.

Campervan wiring is a complex part of any van conversion project.

If you don’t know what you’re doing when it comes to your campervan electrics, get an expert to do it for you.

Automatically Create Your Bespoke RV Wiring Diagram

Includes 110v & 240v, solar, B2B, batteries, inverters, 12v, 24v & 48v systems, wire gauges in AWG & mm² & much more!

Installation hints, tips & safety

a retro VW camper parked up on a cloudy day overlooking a drab countryside scene
  • Only connect the same type of batteries together. So don’t connect an AGM battery with a Gel battery
  • Don’t wire lithium batteries in series without the manufacturer’s specific instructions and controllers
  • Ensure terminals never come into contact with any metal parts of the van
  • Secure batteries so they will not come loose in an accident or vehicle roll over
  • Fit battery isolators where they are easily accessible and identifiable
  • Fit monitoring and energy controllers, fuses isolators and breakers as per manufacturers instructions
  • Install a battery management system to monitor and protect the battery
  • Always wear approved safety glasses or a face shield when working on the batteries
  • Wear proper clothing to protect your face, hands and body when working on the batteries
  • Keep the work area well ventilated – especially if fitting flooded lead acid batteries
  • Never lean over the battery while it is connected to a power source, solar panel, alternator or shore power
  • Disconnect and isolate the battery from external inputs and outputs when working on it
  • Keep away from cigarettes, flames, sparks and other ignition sources – they could cause some batteries to catch fire or even explode
  • Exercise caution when working with metal tools or conductors to prevent short circuits and sparks
  • Keep vent caps and terminal connections tight
  • Should you have direct contact with any battery fluids, flush the area with copious amounts of water and call for medical attention immediately
  • Keep batteries out of the reach of children
  • Always remove the negative terminal first when disconnecting a battery

Graham Bogie

Graham Bogie - Expert in RV & Campervan Electrics - Mowgli Adventures

Graham is a seasoned marine electrical engineer with two decades of experience designing customized electrical systems for plant machinery and converting campers and overland vehicles. His expertise has led him to author the reputable Campervan Electrics Handbook and become the chief designer of our Campervan Electrical Design Service. As a knowledgeable figure in the field, his YouTube channel, blog, Facebook group, and newsletter, offering electrical advice and product reviews, reach more than a million users each year.

1 thought on “How to Choose the Best Campervan Batteries”

  1. Hi, i have 4 12v 200ah AGM batteries i need to connect to form a 24v battery bank, how many Ah and how do i connect together


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