Best leisure battery for a campervan [UPDATED: Dec 2024]

When building an off-grid campervan electrical system, choosing the best leisure battery is crucial for reliable and efficient power. Leisure batteries are designed to deliver a steady flow of energy over long periods, unlike your vehicle’s starter battery, which provides a brief burst of high current. There are two primary types of leisure batteries to consider: lead-acid and lithium-ion (typically LiFePO4).

What are leisure batteries and why do you need one?

Leisure batteries store the power required to run your electrical system. When you charge a battery, energy is generated from charging methods, such as solar and shore hook up. This is converted from ‘electrical energy’ to ‘chemical potential energy’ and stored in your leisure batteries. Then, when you need it, it’s converted back to electrical energy to power your devices.

So, if you want to spend any time off-grid in your campervan, you need to include a leisure battery in your electrical system.

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Important leisure battery qualities to understand

Capacity: the ‘amp hour’ (Ah) and the ‘watt hour’ (Wh)

The capacity of a leisure battery is measured in either ‘amp hours’ (Ah) or ‘watt hours’ (Wh).

• Amp hour (Ah) measures the total amount of electric charge a battery can hold. It indicates how much current (amps) a battery can deliver over time. This metric alone doesn’t account for the voltage of the battery.
• Watt hour (Wh) measures the total energy capacity of a battery, taking into account both the current (amps) and the voltage (V). It gives a more complete picture of how much power a battery can provide.

The formula for calculating watt-hours is:

Watt hours (Wh) = Amp hours (Ah) × Voltage (V)

It’s useful to understand watt hours when comparing batteries of different voltages. For example, a 100Ah 12V leisure battery has half the capacity of a 100Ah 24V leisure battery. This is because:

100Ah x 12V = 1200Wh

100Ah x 24V = 2400Wh

So, it can be useful to think in Wh when talking about leisure battery capacity.

Usable capacity / Depth of Discharge (DoD)

The usable capacity of a leisure battery is what you might expect from the name – how much of the capacity you can use. Where lead-acid batteries can only be discharged by ~50-80% of their total capacity, lithium leisure batteries can be discharged by almost 100%. So, much more of a lithium battery’s total capacity is accessible.

This is sometimes referred to as its ‘Depth of Discharge’, or DoD. A battery’s lifespan will often be given based on a specific DoD, because discharging a battery much more than this will reduce its lifespan. On the flip side, discharging a battery much less each cycle will prolong its lifespan.

Lead-acid vs lithium-ion leisure batteries – which is best for a campervan?

Historically, lead-acid batteries were the go-to choice for van conversions due to their affordability and well-established technology. Among these, AGM (Absorbent Glass Mat) batteries were the most popular. These sealed batteries use a fibreglass mat to contain an electrolyte, making them maintenance-free and allowing for versatile installation (even on their side). A few years ago, AGM leisure batteries were the recommended choice for most campervan setups due to their lower upfront cost. However, the market has shifted as lithium prices have come down, making them a more attractive option.

Why lead-acid batteries are becoming less popular

While AGM batteries are still a solid choice for lower power usage and occasional trips, they come with a few drawbacks:

• Shorter lifespan: AGM batteries typically last around 500 cycles at 80% Depth of Discharge (DoD).
• Heavier weight: A typical 230Ah AGM battery weighs around 59kg, which can significantly affect your van’s total weight.
• Lower efficiency: Due to the Peukert Effect, drawing large amounts of power quickly from a lead-acid battery reduces its effective capacity.

Lithium-ion leisure batteries: the new standard

As the price of lithium batteries has decreased, they’ve become the preferred choice for the majority of campervan builds. Brands like Fogstar have driven this change, making high-quality lithium options more accessible. When comparing price per kWh, lithium batteries are now nearly on par with AGM.

However, when you factor in their extended lifespan, reduced weight, and higher efficiency, lithium-ion batteries often provide much better value. In addition to this, you still require an additional battery monitor with AGM batteries. In comparison, most lithium leisure batteries have a built-in battery monitor. Once you factor in this addition, the cost of the two often reaches parity.

The 300Ah Fogstar Drift PRO.

Key advantages of lithium leisure batteries

1. Longer lifespan: Lithium batteries like the Fogstar Drift 230Ah can last up to 4,000 cycles at 80% DoD, significantly outlasting AGM batteries.
2. Lightweight design: At just 25kg, a 230Ah lithium battery weighs less than half of an equivalent AGM, helping keep your van’s total weight under the 3.5-tonne limit.
3. Higher discharge rate: Lithium batteries can handle higher current draws without significant capacity loss. This makes them ideal for powering larger inverters (3,000VA or more), ensuring you can run appliances like induction hobs, air conditioners, and other power-hungry devices with ease.

What to look for in the ‘best’ leisure battery

So, what makes a leisure battery the ‘best’ leisure battery? Well, there are a few factors and features you should consider:

• Built-in battery monitor
• Cost per Ah
• Max discharge current
• Automatic heating
• Weight and size
• Lifespan
• Warranty

Built-in battery monitor

A built-in battery monitor is certainly a differentiator of leisure batteries. If a battery has a good built-in monitor, this negates the need to purchase a separate battery monitor.

Where pretty much all AGM batteries won’t have a built-in battery monitor, many newer lithium batteries will include one by default.

Cost per Ah

Perhaps the most obvious feature to look at when considering what’s ‘best’ is value for money. By looking at cost per Ah, you can compare two batteries of different capacities and see which one is actually cheaper.

However, remember to factor in additional costs, such as a battery monitor, if one battery has one built-in and the other does not.

Example

Let’s compare 3 batteries: one AGM and two lithium, each with the same usable capacity:

1. TN Power 125Ah AGM
2. Fogstar Drift 105Ah lithium
3. Victron 100Ah smart lithium

AGM typically shouldn’t be discharged more than 80%. In contrast, lithium can be discharged by 95%. This is why we can compare a 125Ah AGM battery with a 100Ah lithium battery.

The Fogstar leisure battery has a built-in battery monitor and BMS (battery management system).

In comparison, Victron lithium batteries needs a separate BMS and battery monitor, so we need to factor these into the cost per Ah.

Similarly, we need to factor in the cost of a battery monitor to the cost of the TN Power AGM battery.

TN Power 125Ah AGM

First, let’s work out the total cost of all the components needed with the TN Power battery:

£221.99 (125Ah battery) + £63.90 (300A SmartShunt) + £27 (Victron temperature sensor) = £312.89

Next, let’s work out the cost per Ah. To do this, we need to work out the usable capacity of the battery:

125Ah x 80% DoD = 100Ah usable capacity

£312.89 / 100Ah = £3.13 per Ah

Fogstar 105Ah lithium

As the Fogstar battery has a built-in BMS and battery monitor, we already know the total cost of the battery. So, we just need to work out the usable capacity to calculate the cost per Ah:

105Ah x 95% DoD = 100Ah usable capacity

£299.99 / 100Ah = £3 per Ah

Fogstar Drift 105Ah – 12V lithium leisure battery

⬤ In stock

£369.00 £299.99 Save 19%

Victron 100Ah smart lithium

For the Victron lithium, we need to add together the cost of all the required components:

£685.99 (100Ah battery) + £113.99 (Victron BMS) + £63.90 (300A SmartShunt) + £27 (Victron temperature sensor) = £890.88

Next, let’s work out the cost per Ah. Once again, we need to work out the usable capacity of the battery:

100Ah x 95% DoD = 95Ah usable capacity

£890.88 / 95Ah = £9.38 per Ah

So, as you can see, the cheapest option per Ah is the Fogstar lithium battery. Even though the TN Power AGM battery itself is cheaper than the Fogstar battery, the addition of the battery monitor makes the total cost higher. In comparison, the Victron lithium battery is a staggering 3 times more expensive!

Max discharge current

The ‘maximum discharge current’ of a battery highlights the maximum continuous current you can draw from the battery. This is a metric specific to lithium batteries. As lithium batteries can be discharged at a very high current, the limiting factor is usually what their internal BMS can cope with.

While cheaper lithium batteries have a lower max discharge current, more premium options have a higher discharge current.

Take for example the 230Ah Fogstar Drift – the maximum discharge current is 250A. In comparison, the 230Ah Drift PRO has a discharge current of 300A. So, the PRO can cope with an additional 50A of discharging per hour.

To calculate your max discharge current, divide your maximum power usage at any one time by your system voltage.

Example

If you have a 12V system with a 2000W inverter and 60A of DC loads:

2000W / 12V = 167A

167A + 60A = 227A max discharge current

So, you could use any of the Drift batteries (other than the 105Ah). These all have a max discharge current of 250A.

Peukert Effect

AGM batteries are much more limited in this respect, due to something called the Peukert Effect. This phenomenon describes how the effective capacity of a lead-acid battery, including AGM batteries, decreases as the discharge current increases. The Peukert Effect is due to increased internal losses and inefficiencies within the battery at higher currents. So, the battery will deliver less total energy than its rated capacity under such conditions.

For example, if you discharge a 100Ah AGM battery by 50A, the effective is approximately 85.5Ah. For this reason, any high current systems will need to use a lithium battery.

Heating

While AGM batteries can be charged and discharged at much lower temperatures, lithium-ion batteries are highly temperature-sensitive. So, their performance and longevity can be significantly impacted by cold conditions. Charging lithium batteries below 0°C (32°F) can lead to plating of metallic lithium on the anode, which is irreversible and reduces battery capacity while increasing the risk of failure.

By incorporating a heater, the battery can pre-warm itself to a safe temperature before charging, ensuring optimal performance and preventing long-term damage. This is especially useful in applications like campervans or off-grid systems where batteries may be exposed to freezing temperatures.

So, if you’re opting for lithium, we’d recommend looking for a leisure battery with a built-in heater. This way, you don’t need to worry about your battery cutting out in cold environments.

Our Off-Grid Engineer Will exploring the colder climates.

Weight and size

When considering the best leisure battery for a campervan, weight and size are both important factors. In a campervan, space is usually at a premium. Additionally, most vans are limited to a gross vehicle weight of 3.5 tonnes. This means that your van, build and everyone inside it cannot exceed this weight limit. Whilst this isn’t an issue for smaller vans, if you are converting a large van you may quickly find that you start to creep towards this limit. Additionally, most people will not be able to drive a vehicle heavier than 3.5T with a standard driving licence. For this reason, it’s best to opt for a battery that is as small and light as possible.

Looking back at our cost/Ah example, the Fogstar lithium and the TN Power AGM were very close, at £3 and £3.13 per Ah.

However, if we factor in the difference in weight and size, it further highlights the benefit of opting for lithium.

So, as you can see, the Fogstar batteries are over a third of the weight of the TN Power AGM! Once you start increasing battery capacity in a larger system, this delta becomes even more important.

Lifespan

Battery lifespan is a critical factor when thinking about the best option for your leisure battery choice. AGM batteries typically have a shorter lifespan compared to lithium batteries, with an average cycle life of around 300 to 500 cycles when discharged to 80% Depth of Discharge (DoD).

Their lifespan decreases significantly if they are regularly discharged deeper due to increased stress on the lead plates, leading to sulphation and reduced capacity. Proper maintenance, like avoiding deep discharges and recharging promptly, can help extend their usable life.

If you will use your campervan every day, an AGM battery will typically last around 3 years, and in this instance, we’d recommend only discharging it by 60% each cycle to maximise its lifespan.

Lithium (LiFePO₄) batteries, have a much longer lifespan. They are often rated for 2,000 to 5,000 cycles at 80% DoD or more. They are designed to handle much deeper discharges without significant degradation. So, they are ideal for applications where battery performance and longevity are paramount.

A lithium battery can often provide up to 10 years of reliable service, compared to 2-5 years for AGM batteries in similar conditions. This is due to their advanced chemistry and lack of issues like sulphation or plate warping, which are common in AGM batteries.

You should factor this in when deciding which option is best for you. If you plan to use your campervan regularly, it’s likely that lithium will be the best leisure battery option for you.

Warranty

Finally, when looking for the ‘best’ leisure battery, you should consider the manufacturer’s warranty. The warranty for most AGM batteries is 2-3 years. For example, TN Power AGM batteries have a 2 year warranty.

In contrast, many lithium batteries will have a 10 year warranty. This is because, as mentioned previously, the lifespan of a lithium battery is much longer than an AGM battery.

Best leisure battery for a campervan in 2024 🔋🏆

So, now you know what qualifies a leisure battery to be the ‘best’, we thought we’d share our opinion on the best leisure battery available in 2024.

Fogstar Drift range

We believe the Fogstar Drift range offers the best balance between quality and cost in the leisure battery market. While the 105Ah leisure battery has a max discharge rate of 100A, all other sizes boast a max discharge of 250A, which is suitable for most 12V campervan electrical systems.

Additionally, the Fogstar Drift batteries all include a built-in Bluetooth battery monitor and heating. This protects the lithium cells if the temperature drops below a certain point, and ensures they keep performing.

The Drift range comes with a long 10 year warranty, so you can be sure your system will keep performing.

Fogstar Drift PRO range

The Fogstar Drift PRO range is worth an honourable mention for those who have a high power system with larger discharge requirements.

Additionally, if you will install a Cerbo GX in your system, the PRO range directly interfaces with Victron components. So, this means you don’t have to purchase an additional battery monitor to connect to the Cerbo GX.

We now include Fogstar leisure batteries as default in all of our bespoke electrical systems. Get in touch if you’d like help from one of our engineers with your campervan electrics ⚡

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