Caravan Tow Vehicle Charging Wiring

After getting the brake controller installed in your vehicle, another major component of a good electrical system is a charging system from the tow vehicle to the caravan.

This on-the-road charging system will keep your fridge running optimally, charge your house batteries, and keep your emergency braking system fully charged and ready.

There are many different options when it comes to wiring in a charging system from the tow vehicle to your caravan. Unfortunately, many installations are very poor resulting from a lack of understanding of the intracacies of 12V DC power, and the requirements of a caravan. The main problems we see are:

  1. Under-rated cable size – leads to low charging rates – as little as just 10% of what is possible, and poor fridge operation on 12V (ie allowing fridge to heat up)
  2. Incorrect signal wires – not understanding the requirements of the van's fridge computer and in-built 240V/12V charging system resulting in the van being confused what power to run from
  3. Lack of isolation for when the vehicle is turned off – ie when you stop the car, you should not be running the risk of flattening your car's starter battery.
  4. Incorrect charging of the emergency brake system – resulting in the emergency system regularly being flattened with normal caravan usage.
  5. Incorrect circuits within the van that allow the 12V fridge element to run from the caravan's house batteries.

Good quality installations use heavy duty charging cable through an Andersen plug. The size of cable being dependent on the length of the run, which is determined by the position of the house batteries in the vehicle. Normal wire sizes we use are 8B&S or 6B&S, nothing smaller. We use a number of relays in the van to ensure 100% isolation of the tow vehicle's starter battery, emergency braking system, and also the 12V element of the fridge – ensuring your house batteries get the maximum possible charge, your fridge runs at 100% and your emergency braking system is always as fully charged as possible.

We offer a range of upgrades within the charging system to include DC-DC chargers which can improve the house battery charge levels by up to 40% – giving you more days away from a power point, integration with solar systems, dual battery systems within the vehicle, and upgraded electrical plugs/couplings – making the hitching/unhitching process much easier!

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506 Boundary St
Toowoomba QLD 4350

(Cnr Gardner Ct)

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