What is a brake controller and how do they work? : Elecbrakes

If you’re planning an adventure, you’ve no doubt considered all the great aspects of the journey, along with some of the things that could go wrong. You have fitted your roof racks and bike carrier, your LED lighting attached, solar blankets and wheel covers packed into the tool boxes, and your towing mirrors are set up and ready to go. 

You’ve packed your marine fuel for the boat, making sure all your battery accessories are there for your dual battery pack, and you have your power tools, air compressor and pressure washer ready for the off-roading adventure of a lifetime.

Now it’s time to attach your trailer or caravan to your vehicle, which means understanding everything you can about the towing brakes and braking accessories. Including their necessity when it comes to safe travels.

The importance of quality towing and brake controllers

Chances are, you are already aware that it takes more than just the tow vehicle’s brakes to bring the vehicle itself and its trailer to a complete stop within a suitable time frame. Considering trailer weight and speed, it becomes clear the trailer also needs to pitch in with its braking power.

This is accomplished via the trailer’s brakes, which can be one of two types: surge (mechanic or hydraulic), which relies on inertia to slow down automatically, or electric brakes, which require an electric connection to the tow vehicle to work. The principle behind surge (also known as override or overrun) brakes is simple.

The coupling contains a sliding shaft attached to the tow ball. The shaft slides when pushed due to the vehicle slowing down and exerts pressure directly on a mechanical linkage (mechanical brakes) or a link connected to a hydraulic cylinder, which in turn creates hydraulic pressure on the braking system (hydraulic brakes). These are often found on camper trailers or boat trailers.

Electric trailer brakes work by activating electromagnetic brake drums to create attrition and slow the trailer down. While surge brakes operate independently, electric trailer brakes must be connected to the tow vehicle’s power and regulated by a brake control unit or electric brake controller.

What is a brake controller?

A brake controller is an electronic device that activates and, as the word suggests, controls the electric brakes of a trailer. 

A brake controller can be roughly split into an interface positioned in the cab within the driver’s reach and the central part responsible for activating the trailer’s brakes. Electronic brake controllers can be classified into non-proportional, time-based, proportional or inertia-based types.

How do older brake controllers work? 

Older non-proportional electric brake controllers are activated when the driver presses on the car’s brakes, applying braking force over time based on the chosen setting. 

The drawback of this kind of brake controller is that even though the pressure applied on the tow vehicle’s brake pedal can vary (for instance, compare a gentle brake to an abrupt one), the response of the trailer brakes will be the same, the one configured in its settings. 

How do newer brake controllers work?

The newer proportional electric brake controllers measure the changing momentum, or inertia, of the moving car via an accelerometer; they are not directly connected to the car’s brakes and work independently of them.

 Continuously monitoring the vehicle’s dynamics, these controllers send the precise amount of voltage to the trailer brakes to ensure that the speed of the trailer matches that of the tow vehicle. This generally makes for a smoother braking experience and more efficient braking, ensuring your trailer brakes last longer.

For instance, when going downhill, you’ll want to use lower gears to slow down to decrease brake wear; inertia-based brake controllers sense that the vehicle is slowing down (rather than the vehicle’s brakes being applied) and adjust trailer braking power accordingly. 

The drawbacks of in-car installations

Conventionally, electric brake controllers have been installed “in-car”. That is, they had to be hard-wired aftermarket within the vehicle for towing. The interface would be mounted in the least obtrusive position in the cab but within reach of the driver’s seat. This would be traditionally accomplished by drilling holes into the dashboard, fixing the provided mounting brackets with screws, and attaching the interface to these brackets. 

The wiring would then be connected to the vehicle’s wiring loom and ran to the rear, terminating at the vehicle’s trailer adapters. This translated into the necessity of having a new brake controller fitted every time one used a different vehicle for towing purposes. For instance, when the trailer is lent, hired, or there is a vehicle upgrade.