So you have a caravan with electric brakes…..What now?

electric brake controllers

If you have just purchased a caravan that has electric brakes you might be wondering what are electric brakes, what is an electric brake controller or even wondering if you need electric brakes. There are so many articles out there about the legal requirements of electric brake controllers, but we often have customers whose trailer or caravan might be just under the legal limit. Often these customers question why they would install electric brakes or electric brake controllers if legally they aren’t required. We are going to run through some frequently asked questions about electric brakes and electric brake controllers.

Do I need Electric Brakes?

The legal answer:

Regulations state that trailers which weigh 750kg GTM* or less AND have a single axle will not require a braking system.

Anything – including trailers, horse floats, boat & trailers and caravans, which exceed the 750kg GTM limit legally require having an efficient braking system on at least one axle.

It is also a legal requirement that all caravans, trailers and floats exceeding 2000kg (GTM) are fitted with an efficient braking system on all wheels.

Electric brakes are the most common form of an “efficient braking system” and come standard on most camper trailers and caravans.


Single axel

750kg – 2000kg2001kg – 4500kg
Electric Brakes Required?No Brakes requiredYes – must be fitted with an efficient brake system considered to have brakes operating on the wheels of at least one axelYes – must be fitted with an efficient brake system must have brakes operating on all wheels
Brake Away UnitNANAThe brake system must cause an immediate application of the trailer brakes in the event of the trailer becoming detached from the towing vehicle. Under these circumstances, the brakes must remain applied for at least 15 minutes.


What are electric brakes?

On the caravan or trailer you have drum brakes – pretty much the same as drum brakes in a car – Check out this youtube video for a great explanation.

How do Electric Brakes & Electric Brake Controllers work?

The trailer or caravan brakes will not work unless you have an Electric brake controller in your car.

When the towing vehicle’s stop lights are activated, power feeds into the electric brake controller. A heavy duty circuit fed through the trailers connecting plug and socket then triggers the trailers brakes. This allows the trailer brakes to come on automatically when the vehicle’s brakes are applied. When adjusted correctly, the controller allows the driver to slow the combined tow vehicle and trailer just as smoothly as an uncoupled tow vehicle.

It’s important the wiring is heavy enough to allow the power to run through to the trailer. It also needs to have a good earth return, not just an earth to the body.

Proper maintenance of the brakes with regular adjustment of the shoes and care of the magnets is also important.

What do electric brake controllers do?

The in-car electric brake control units rely on a pendulum effect to detect braking. Deceleration swings the pendulum inside the unit forwards activating the electric brakes.

Earlier models and the current budget models have a manual adjustment for the in unit’s pendulum. The more upmarket models have automatic adjustment and tend to be smoother when the caravan/camper trailer brakes are applied. However, they do cost a bit more.

Why are Electric Brake Controllers so important?

Electric brake controllers ensure the safety of the occupants in the tow vehicle as well as other drivers on the road. They allow more control over the braking force of the caravan or trailer and limit the pressure on the tow vehicle’s brakes. Noticeable differences when driving with an electric brake controller include less push from behind, easier and quicker stopping. You should also notice a reduction in the jarring of the linkages. By using an electric brake controller, the likelihood of jack-knifing and being overtaken by own caravan or trailer is reduced.

Types of Controllers

There are two types of electric brake controllers. Motion sensing also called pendulum style and time delay activated or also known as solid state. Despite the controller’s methods being different, both types of controllers are very similar. Both types have the same wiring configuration and allow the user to adjust braking power. Both also have a pressure sensitive manual over-ride trigger. This allows the trailer brakes to work independently of the vehicle’s brakes.

MOTION SENSING (Or pendulum style controllers) are activated by a pendulum circuit. Enabled by the brake pedal switch, the controller senses the vehicles stopping motion and applies a proportional voltage to the trailers brakes. When configured correctly the trailer will decelerate at the same speed as the tow vehicle. This increases braking efficiency and reduces brake wear. Pendulum style electric brake controllers work well under adverse braking conditions and have a smooth braking action. However, most pendulum style controllers are bulky, expensive and must be mounted and calibrated on level ground.

TIME DELAYED controllers are inexpensive, have a low profile and can be mounted on any angle. They work by operating at a pre-determined braking rate and are designed to activate the brakes on a set delay. In some cases, the rate of brake application for a gradual stop or an attempted emergency stop is the same. So while time delayed electric brake controllers provide some braking they do not provide the most efficient balanced braking for combined tow vehicles and trailers.

Which is the best?

We’re huge fans of the Redarc Tow-Pro range. It can be set to both a motion sensing and time delay and due to its additional safety benefits.

The Tow-Pro™ Elite brake controller offers selectable Automatic or User Controlled trailer braking modes. This allows the user to choose the braking style depending on the road or terrain conditions, vehicle type, or driver preference.
The Tow-Pro™ Elite electric brake controller features Active Calibration which constantly monitors the direction of travel. The unit will even calibrate with no trailer attached whilst maintaining the ability to mount in any orientation.

If budget is a constraining factor then we’d recommend an entry level Tekonsha. I’ve currently got one installed in my Landcruiser and it does the job. It doesn’t provide the smooth driving experience like the Redarc Tow Pro, but we have found them to be totally trouble free. The Tekonsha units have a lot of fans.

Can I wire the electric brake to my foot brake to save some money?

No. This could cause accidents, void warranties and insurance policies and is illegal.


GTM: it is the weight of the fully loaded trailer (water, food, clothes, chairs, esky, dog, beers….) imposed on the trailer’s axle when it is coupled to the tow vehicle. The most accurate way to get your GTM is to load the trailer or caravan up and drive it onto a weigh bridge (vehicle wheels not on weighbridge).

ATM: The weight of a fully loaded trailer (or caravan, float, boat and trailer) when it is not coupled to a tow vehicle.
