camper van electrical systems
Campervan electrics explained
Before we dive into the nitty gritty of campervan electrics, it’s useful to understand how electricity works. Electricity is defined as the flow of electrons in a material. This is referred to as electrical charge, or ‘current’, and is measured in amps. Voltage is defined as the potential energy in a system, which is required to make the current flow. You can measure the flow of current per hour using the amp hour (Ah).
The easiest way to think about a campervan electrical system is as a number of inputs (these are how you charge your system) and a number of outputs, usually referred to as ‘loads’ (this is what keeps your lights on and your fridge cold!). There are two possible types of load in a campervan: 12V and 230V. A standard car battery is 12V, and so are most leisure batteries. These have a direct current (DC). Mains powered appliances have an alternating current (AC). You can use an inverter to convert the DC current to an AC current, which will allow you to run 230V appliances. You can read more about converting DC to AC on our page dedicated to inverters.
Charging your leisure batteries
There are a number of options when it comes to the ‘inputs’ for your camper van electrical system:
- Solar power
- Shore hook up (via a battery charger or MultiPlus)
- Vehicle alternator (via a VSR or battery to battery charger)
The device you choose will largely depend on how you plan to use your campervan. If you will spend a lot of time on a campsite, it makes sense to install a shore hook up point on the side of your campervan. If you plan to spend most of your time off-grid, you should consider solar panels and a VSR or battery to battery charger. You can read more about each option on our detailed guidebook pages:
Electric hook up
VSRs & DC-DC converters
Campervan leisure batteries
Leisure batteries are the core of any campervan electrical system, as they store the charge required to power your appliances and keep your lights on! There are a number of different types of leisure battery available, and the type and size you will need will depend on your usage.
Flooded lead acid batteries
For a long time in the caravanning and boat world, the most common type of battery was the flooded lead acid (FLA) battery. These batteries are ‘flooded’ with a liquid electrolyte (a substance that conducts electricity), and unsealed FLA batteries needed to be maintained regularly by topping them up with de-ionised water. Nowadays a sealed flooded lead acid battery is available, commonly referred to as ‘maintenance-free’. Flooded lead acid leisure batteries cannot be discharged below 50% of their total capacity as this can cause irreparable damage.
AGM & gel batteries
AGM and gel leisure batteries both use lead acid technology, but rather than being ‘wet’, it is contained in either a gel or a fibreglass mat. AGM and gel batteries have a longer lifespan than flooded lead acid batteries and can also be more deeply discharged, but they are also more expensive, heavier and more sensitive to overcharging. AGM batteries are a popular choice for campervans, as gel batteries need to be charged in a very specific way.
Lithium ion batteries
Lithium has become a popular choice for batteries over the past few years as it has a much longer lifespan than any other battery on the market, and they can be extremely deeply discharged. They are also much lighter and smaller than lead acid batteries. However, lithium leisure batteries have an extremely high upfront cost, and are usually overkill for a campervan electrical system.
To learn more about campervan leisure batteries and how to calculate your expected battery usage, visit our campervan leisure battery guidebook page (coming soon!).
Our free electrical system design service, making off-grid energy simple
Need help sizing your camper van electrical system?
If you’re confused about how many solar panels you need, or not sure how big a battery bank to install, try out our electrical system calculators. They will help you figure out exactly what components you need to make your campervan electrical system work for you!
Solar panel calculator
Charge controller calculator
Camper van electrical system blog posts
Our electrical system blog posts include wiring diagrams, as well as useful tips and advice about how to install your electrical system and mount solar panels to your campervan roof.