Choosing a leisure battery for a campervan

Anyone who travels by motorhome knows that a well-functioning battery is very important. Motorhomes consume a lot of electricity, which also explains why they usually have two batteries: the starter battery and the leisure battery. The latter is essential to power your equipment, such as lights, pump or a fridge. In order to help you to figure out which kind of leisure battery to choose, we will present the pros and cons of each one and show you how to determine your electricity consumption and the required battery storage capacity.

Leisure battery types for a motorhome

Flooded lead acid (FLA) batteries

These are the oldest motorhome batteries and one of the cheapest. The way they work is that they contain a combination of lead and sulphuric acid, which causes a chemical reaction to provide electricity. Important to know is that flooded lead acid batteries need a lot of maintenance. With ongoing use, the acid evaporates, which means that the battery has to be recharged frequently and reaches its end date rather quickly. With regular maintenance you will be able to use it for about 5-8 years. A big advantage apart from the price is the fact that these kinds of batteries can be found everywhere and in all sizes.
Today, FLA batteries are no longer considered high tech batteries and more and more replaced by gel, AGM and lithium-ion batteries.

Advantages:

+ low purchase price
+ large range of sizes
+ resilient to occasion over charging
+ regular maintenance and careful recharging necessary

Disadvantages:

- lifespan limited to 5-8 years
- possibility of release of dangerous gases in case of lacking maintenance and insufficient ventilation

Gel batteries

Gel batteries work quite similar to FLA batteries, except that they use a gel instead of liquid. While they are almost maintenance free, they do require a special charging technique.This is due to the oxyhydrogen gas contained in the battery, which, if used incorrectly, could lead to explosions in the worst case. But don't worry, gel cell batteries are built in such a way that nothing can leak out.

Advantages:

+ almost maintenance free
+ no ventilation needed
+ longer life expectancy than FLA 
+ good performance in warm and cold conditions
+ usable for seasonal use

Disadvantages:

- life expectancy reduced if drained by more than 80%
- more expensive than FLA and AGM batteries
- heavier than FLA batteries

In case you will take your campervan to areas with temperatures below 0°c, you should choose gel batteries, as they are the only ones able to withstand cold temperatures. 

Absorbed glass mat (AGM) batteries

AGM batteries have a similar functionality as FLA batteries, the only difference is that they use ctrolyte soaked glass fibres. As they are dry, they do not need a vent and there is no risk of gases. 

Advantages:

+ maintenance free
+ lighter and smaller than gel batteries
+ longer life expectancy than FLA
+ seasonal use possible

Disadvantages:

- life expectancy reduced if drained by more than 80%
- more expensive than FLA batteries
- reduced performance in cold climates

Lithium battery

The lithium battery revolutionised the motorhome world a few years ago! It stores more electricity, even though it is smaller and lighter than other batteries and it is maintenance-free. It is certainly a pricier option than gel, FLA or AGM batteries, but it comes with a longer battery life and a quicker charging time. 

Important when buying a lithium battery is to take care that a battery management system is included (or bought separately) in order to protect it from discharging and over charging. 

Advantages:

+ even smaller and lighter than AGM batteries
+ deliver over 90% of their capacity
+ charge quickly
+ long life expectancy

Disadvantages:

- no functioning in degrees below 0°c
- expensive
- more difficult to find: not the best option if visiting remote locations and developing countries
- special charger needed to reactivate it if it is discharged to zero

How to determine your required battery storage capacity

1. Calculate your electricity consumption

Make a list of all your electrical devices (such as fridge, laptop, phone charger, water pump etc.) and note how many amps each one consumes. You should find the power draw (either in amps or Watts) on the device’s manual or label. 

2. Determine amp-hours

Write down your estimations of how long each device will be used (differentiate the time it is just plugged in and the time it is actually used). Multiply each device's amp consumption with the number of hours of use. That will allow you to sum up the total daily amp-hours of all your devices.

3. Determine days off-grid

How many days do your batteries have to last? This depends on how often will you have access to mains and if you will do a lot of wild camping. It also depends on whether you dispose of solar power or an engine alternator charging system. 

4. Get battery storage capacity

Multiply the daily amp-hour use by the number of days off-grid. The result will be your required battery storage capacity, which will give you a hint at which battery type will be suitable for your needs and how many you need. Keep in mind though that batteries cannot be drained completely and that they are not 100% efficient! FLA batteries are only about 50% efficient, gel and AGM about 80% and lithium-ion more than 90%.

It can certainly be a tricky business to choose the right batteries for your campervan. We recommend you to look for best-practice advice and experiences of your fellow vanlifers. You will find a lot of detailed information online, which might help you in your decision making process. Hopefully this article could already answer some of your questions and brings you one step closer to your very own campervan. If you already have a campervan and would like to generate additional income, go visit Yescapa to hire out your vehicle!