Campervan Leisure Batteries

A leisure battery is a deep-cycle battery designed to provide steady power over long periods, making it ideal for campervans, motorhomes, caravans and off-grid electrical systems. Unlike a standard starter battery, which delivers a short burst of power to start an engine, a leisure battery is built to repeatedly charge and discharge while powering appliances such as fridges, lighting, diesel heaters, USB sockets, water pumps and inverters.

In campervan conversions, leisure batteries are the heart of the 12V electrical system and allow you to run equipment without draining your vehicle’s starter battery. They can be charged through a split-charge relay, DC-DC charger, mains hook-up or solar panel system depending on your setup.

There are several types of leisure battery available, including Lead Acid, AGM and lithium, each suited to different budgets and power requirements.

Choosing the right leisure battery depends on your budget, electrical setup and how often you camp off-grid. The three most common types used in campervans and motorhomes are lead acid, AGM and lithium batteries.

Lead Acid Leisure Batteries

Traditional lead acid leisure batteries are the most affordable option and are commonly used in basic campervan or caravan setups with lower power demands.

• Benefits of lead acid batteries:
  
• Lowest upfront cost
  
• Simple and widely available
  
• Suitable for occasional use and smaller electrical systems
  

However, lead acid batteries are heavier, slower to charge and generally have a shorter lifespan than AGM or lithium batteries. They also require more careful maintenance and should not regularly be deeply discharged, as this can reduce battery life significantly.

AGM Leisure Batteries

AGM (Absorbent Glass Mat) batteries are a more advanced type of lead acid battery designed for improved durability and performance. They are sealed and maintenance-free, making them a popular choice for campervan electrical systems.

Benefits of AGM batteries:

• Maintenance-free design
  
• Better vibration resistance
  
• Faster charging than standard lead acid batteries
  
• More reliable for regular campervan use
  

Compared to standard lead acid batteries, AGM batteries offer better performance and longer lifespan, although they are still heavier and less efficient than lithium options.

Lithium Leisure Batteries

Lithium leisure batteries are now considered the premium option for modern campervan conversions and off-grid electrical systems.

Benefits of lithium batteries:

• Much lighter weight
  
• Faster charging
  
• Longer lifespan
  
• Higher usable battery capacity
  
• Better efficiency for off-grid camping
  

Lithium batteries can safely discharge much deeper than lead acid or AGM batteries, meaning more usable power from the same rated capacity. They are also ideal for vans running larger electrical loads such as:

• inverters
  
• induction hobs
  
• coffee machines
  
• large fridges
  

Although lithium batteries have a higher upfront cost, their longer lifespan and improved performance often make them the best long term value for frequent campervan use.

Which Battery Type Is Best?

As a general guide:

• Lead acid batteries are best for basic/budget builds
  
• AGM batteries offer a good balance of cost and reliability
  
• Lithium batteries are ideal for serious off-grid camping and modern campervan electrical systems
  

The best option depends on your power requirements, charging setup and how you use your van.

The right leisure battery size depends on your power usage, trip length and whether you regularly camp off-grid.

Smaller setups using lighting, USB charging and occasional appliance use may only require a 100Ah battery. Larger campervan electrical systems with compressor fridges, diesel heaters, inverters and solar charging often benefit from 200Ah or more, particularly when using lithium batteries.

As a rough guide:

• 100Ah AGM — suitable for weekend camping and lighter power usage
  
• 100Ah Lithium — ideal for most campervan conversions with moderate off-grid use
  
• 200Ah+ Lithium — best for extended off-grid travel and higher-demand appliances
  

Lithium batteries also allow deeper discharge without damaging the battery, meaning a 100Ah lithium battery often provides similar usable power to a much larger AGM setup.

If you're planning a full electrical installation, it’s also important to choose compatible charging equipment, including DC-DC chargers, solar controllers and battery monitors.

How long a leisure battery lasts depends on:

• battery size
  
• battery type
  
• appliance usage
  
• charging setup
  
• time spent off-grid
  

The biggest power draws are usually:

• compressor fridges
  
• inverters
  
• charging laptops and devices
  

Lithium batteries typically provide significantly more usable power than AGM or lead acid batteries because they can safely discharge deeper without damaging the battery.

Examples

Weekend Camper Setup

100Ah AGM battery

Typical usage:

• LED lighting
  
• USB phone charging
  
• Water pump
  
• Occasional diesel heater use
  

Expected runtime:

• Around 1–2 days off-grid before recharging
  

Typical Modern Campervan Setup

100Ah Lithium battery

Typical usage:

• Compressor fridge
  
• Diesel heater
  
• Lighting
  
• USB charging
  
• Roof fan
  
• Laptop charging
  

Expected runtime:

• Around 2–4 days off-grid depending on weather and usage
  

Larger Off-Grid Electrical Setup

200Ah Lithium battery

Typical usage:

• Large fridge
  
• Diesel heater
  
• Inverter
  
• Coffee machine
  
• Starlink or laptop charging
  
• Multiple device charging
  

Expected runtime:

• 4+ days off-grid, especially when paired with solar charging
  

What Affects Battery Runtime?

Battery life can vary significantly depending on:

• outside temperature
  
• heater usage
  
• solar input
  
• inverter use
  
• charging frequency

Adding solar panels or charging while driving can dramatically extend off-grid runtime and reduce the need for mains hook-up charging.

Lead Acid vs AGM vs Lithium Runtime

Although a 100Ah AGM and 100Ah lithium battery may appear similar on paper, lithium batteries provide much more usable capacity in practice.

Typical usable capacity:

• 100Ah Lead Acid: ~50Ah usable
  
• 100Ah AGM: ~50–70Ah usable
  
• 100Ah Lithium: ~90–100Ah usable
  

This is one of the main reasons lithium batteries are increasingly popular in campervan electrical systems.

When building a campervan electrical system, multiple leisure batteries can be connected together to increase either voltage or capacity. This is done using either a series or parallel battery setup.

Batteries Connected in Parallel

A parallel setup increases battery capacity (Ah) while keeping the voltage the same.

For example:

2 x 12V 100Ah batteries in parallel = 12V 200Ah system

Parallel wiring is the most common setup for campervan leisure batteries because most campervan electrical systems operate on 12V.

Batteries Connected in Series

A series setup increases voltage while keeping battery capacity the same.

For example

2 x 12V 100Ah batteries in series = 24V 100Ah system

Series wiring is less common in standard campervans.

Remember, all charging equipment and appliances must match the system voltage.

Leisure batteries can be charged in several different ways depending on your campervan electrical setup.

Charging While Driving

Most modern campervan conversions use a DC-DC charger to safely charge the leisure battery from the vehicle alternator while driving. This is especially important for lithium batteries and smart alternator vehicles.

Solar Charging

Solar panels are one of the most popular ways to keep a leisure battery charged while off-grid. Combined with an MPPT solar controller, solar charging helps maintain battery levels during camping trips without needing hook-up power.

Mains Hook-Up Charging

When connected to a campsite electrical hook-up (EHU), a mains battery charger can recharge and maintain your leisure battery safely.

Charging Considerations

Different battery chemistries require different charging profiles. Lithium batteries should always be paired with compatible charging equipment to maximise performance and battery lifespan.

A properly designed charging system helps:

• improve battery efficiency
  
• increase battery lifespan
  
• reduce charging times
  
• support reliable off-grid camping