Caravan Batteries and Related Wiring

With the wonderful National Park facilities and increased emphasis on camp friendly roadside stops as well as a shortage of caravan park sites during peak periods, it is not surprising that we are seeing a growing demand from our customers to stay away from powered sites and begin to install caravan batteries. However, to move away from powered sites you need to know the important facts about caravan batteries.

Some frequently asked questions include, “what’s involved in installing a battery into my caravan?”, “how long can I use the battery for” and “how do I maintain the battery charge?”

We answer some of these questions below, but if you prefer more customised information or are looking for an installation quote for your caravan batteries  please contact the team at Swift Hardings.

The Critical Issues

Type of battery and its location in the caravan

Commonly the customer has a choice of three types of batteries, all of which have their advantages and disadvantages.

  • Conventional Motor Vehicle Battery
  • Deep Cycle Lead Acid Battery
  • Sealed Battery

A conventional motor vehicle battery is well priced and is capable of being swapped into the car in the event of the car’s battery failing. Against this it may struggle to recover in the event of being flattened after a week of use at a National Park. This is a consequence of its design. They were built to be maintained at close to full charge by the regulator of a motor vehicle.

In contrast a deep cycle battery is designed to fully recharge from flat with no compromise to its life expectancy. This has to do with the construction of the plates within the battery itself. So if you are going to be using the battery without the ability to steadily recharge, a deep cycle battery will be advantageous. On the other hand they have less cranking power than a car battery and may not be able to start your engine if called upon to do so. They are also more expensive.

An issue with both these batteries is where to put them? They need external ventilation to expel gases and access for maintenance. Often under a seat box or in a dead front corner is good utilisation of space and this is fine for the battery given that the position is vented to the outside. However you will also need to check fluid levels periodically so access must be practical. We have seen a number of batteries fail prematurely because fluid levels have been ignored due to difficult access. Note: SWIFT HARDINGS can fit an external vented access door with a slide out tray for easy battery maintenance. This is a great help for batteries tucked away.

A sealed battery may be an advantage for utilising a dead floor space somewhere in the van. It will require no ventilation and no regular access for maintenance. They are quite expensive but very convenient.

How to keep the battery charged.

SWIFT HARDINGS recommendation is for charge by battery charger, solar panel or both. Whilst in theory the car has the ability to charge the caravan’s battery whilst you are driving we suggest utilising that capacity to run the caravan fridge on twelve volts and leave it at that. The installation required (heavy cabling and a battery management system) for car to caravan battery charging is expensive and no help to you when you are stationary.

A regulated battery charger connected to the caravan battery will ensure that you leave a powered site fully charged. This is essential. If you are running a few twelve volt lights and a water pump then a decent size battery (say 65 amps) will keep you going for at least 3 or 4 days. Other appliances such as 12 volt televisions and invertors could significantly reduce this period. A solar panel will make you self-sufficient. Usually fitted to the roof of the caravan or pop top this will maintain your battery in all but the worst weather. Some people like to have portable panels that they can move around over the course of the day to maximise input. However mount a decent size panel, say 80 watts capacity, and this will generally provide enough power even on shady sites. Wouldn’t you rather be off fishing or sightseeing rather than monitoring your solar panel all day! A 12 Volt System should be a delight to own because you are free to do your own thing in fantastic camping locations.

Most important is the need to keep some charge up to any type of battery when it is not in use. Batteries all discharge to some extent when the van sits at home during the off-season. In fact they are more likely to fail prematurely from lack of use not over use! A regulated charger (that is turned on!) or solar panel will keep the battery healthy when not in use. Think of your battery as “a living thing” that needs feeding all the time.

Relationship to the caravan fridge

Swift Hardings recommend keeping the caravan battery and the caravan fridge absolutely separate. We particularly do not want the 12 volt element of the fridge connected to the caravan battery. The fridge needs at least 10 amps (around 6 times more power than an internal 12 volt light) and this will draw down your caravan battery too quickly. Swift Hardings will set up you car to run the caravan fridge on 12 volts whilst you are driving. Upon arrival at the campsite switch your fridge to gas and relax. Read more about this.

Conventional Motor Vehicle Battery Deep Cycle Lead Acid Battery Sealed Battery

Price approx.
Benefits Battery capable of being swapped between caravan and car in the event of Car Battery failure. Battery capable of recovering fully after being flattened. No monitoring of fluid levels required.
Caravan battery split from fridge System
No need to check battery fluid level
Fully regulated charger installed
No ventilation required
Full 12V circuit protection
Periodic charging required
Volt Meter upgrade option
Solar upgrade option
Slide out access door option
  • Caravan battery split from fridge system: No risk that the caravan fridge can flatten the caravan battery.
  •  No need to check battery fluid levels: An obvious advantage!
  • Fully regulated charger installed: A Regulated Battery Charger is connected to your battery to allow charging when connected to mains power.
  • No Ventilation required: Conventional Batteries must have some type of ventilation. Swift Hardings can install a vent or access door.
  • Full 12Volt circuit protection: A fuse will be installed between your battery and the caravan 12V circuit to protect the system.
  • Periodic charging required: All batteries need regular charging to stay healthy.
  • Volt Meter upgrade option: A Volt Meter can be installed to eliminate the guesswork on battery condition.
  • Solar upgrade option: An 80Watt Solar Panel is installed on the roof and connected to the battery via a Regulator and Amp & Volt meters.
  • Slide out access door option: For easy battery access and maintenance a door and slide out tray are fitted to a dead storage spot in your caravan


For more information about caravan batteries or to request a quote, please contact us!