One of the most important pieces of equipment any caravan owner can buy is an electric brake controller but choosing the right one can be tricky. After having used and installed a few different types, I have learned a few lessons the hard way that I hope no one else will make.
Electric Brake controllers come in a few different flavours but can be classified as three different types:
- Intelligent Proportional controllers which sense the tow vehicle’s rate of braking and apply the same amount of braking to the caravan
- Standard controllers allow you to adjust the amount of brake applied and also how softly the braking will be applied
These days, most controllers on the market will be either the standard brake controllers or the intelligent proportional controllers but if you have an existing system or purchasing an older car, you may come across the basic type controllers.
So why does it matter which type of controller you get? As far as the legal requirements are concerned, both types will satisfy the requirement (check out our article on the caravan braking systems here which explains what is required depending on your caravans’ mass). The subtleties of which one is better can have a significant impact on how nicely your car will drive over a range of conditions without a lot of input from you. To explain this in practical terms, let’s have a look at how each the two controllers work and then a couple of different scenarios that will be encountered on any trip to see which type is best and why.
How are the two systems different?
Both the Intelligent controller and the standard controller will work in the exact same way if we only look at how they activate the caravan brakes. This is, as the brakes are applied, they will give a changing voltage to the caravan’s brake to change how much the brakes are applied. I.e., more voltage equals stronger braking. This is good because it means that either system can be fitted without needing to change the hardware on the caravan.
The main difference between the two is how they work out how much braking they should be applying. The standard controller generally has two adjustments that can be made while driving, the gain and the ramp. The gain determines how strongly the brakes are being applied, the ramp sets how gently the gain is introduced to the caravan. Think of the gain as how far you actually push the brake pedal down and the ramp as how long it takes you to get the final brake pedal position. A steep ramp is like you pressing the brake pedal fast and going from cruising to full braking in a very short space of time. A gentle ramp is like you are driving your grandmother to dinner and each brake application is slow and considered event that takes a while to take effect but keeps your granny from criticising your driving style.
To give you an idea of a typical brake application from a standard controller, try to imagine the following. Let’s assume that you have your gain set to a medium level of braking and the ramp to allow for a short build-up of brake application (let’s just presume that the controller will take two full seconds to go from no braking to maximum braking). When you press the cars brake pedal, regardless of how hard you press, the brake controller will receive the signal that the brakes are being pressed and will start its brake application procedure. Now, because the ramp is set to a slow build up, the brakes of the caravan start to apply more and more braking effort. This will continue to build until the controller reaches the maximum gain (the maximum level of braking you set).
The trick here is that it doesn’t matter whether you were pressing the brakes really hard or just applying a very light amount of braking pressure, the standard controller will go through the same procedure and will apply the same brake application irrespective of speed or tow vehicle’s motion.
Hence, in a standard controller, both the gain and the ramp will need to be changed depending on your caravan’s load, speed, road conditions and the type of braking your vehicle is undergoing. This usually means that you as the driver will be making a lot of adjustments throughout each different section of your trip.
The intelligent controllers work a little differently. Inside the unit, they have an Inertial Measurement Unit (or IMU) which uses a few different sensors to measure your cars motion by looking at its speed as well as its acceleration or deceleration. In addition to this, there is also a switch which checks if the brake pedal is being pressed.
On the intelligent controllers, the gain is still set by the driver but the ramp is determined by the controller. Understanding how your cars motion allows the ramp to adjusted automatically to match the tow vehicle’s motion providing an overall better brake application. Some modification to the gain is also made by the controller but only to keep the caravans braking effort consistent with the tow vehicle.
The difference in overall towing and braking experience can be understood best through examples.
On almost any caravan trip, there will usually be a couple of different scenarios that will require the caravan brakes to be applied in different ways to give you the best level of safety and comfort. Our four scenarios are
- General braking at high speed like slowing down for an upcoming speed sign change
- Braking at low speed while driving through populated areas or parking
- Emergency braking
General braking at high speed
This type of braking is bound to happen several times in any trip. Imagine you are cruising down the road and there is a change in speed from 90 to 70 or the vehicle in front of you slows down to turn off the road. This scenario only requires gentle braking.
If you have a standard controller, the chances are your braking parameters (gain and ramp) have already been set and as you apply the brakes, the caravan brakes ramp in gently and you feel the caravan tugging you back. This is probably the most forgiving type of braking scenario being that most settings of gain and ramp will be useable even though they may not be ideal.
The intelligent controller in the same situation will match the braking effort of the car and you will likely not even register that you are braking with a caravan attached. This is because the controller will monitor the motion of your car and adjust the gain and ramp to suit.
Braking at low speed
Low speed braking is probably the most frustrating type of braking scenario to experience with a standard controller. When entering a town or even tootling around a caravan park to find your site, if you don’t have the gain and ramp dialled right down for the slow speed driving, you will likely find the caravans brakes almost jerking your car to a halt as the ramp reaches its peak and applies the maximum level of braking effort. This can be an extremely frustrating drive and quite often add a lot of frustration to what can be an already stressful situation (let’s face it, driving around towns and caravan parks with a caravan can be a little nerve racking for most new to the experience).
On the other hand, an intelligent controller will sense that the vehicle is moving and braking slowly in this environment and will match the braking effort perfectly. You certainly won’t feel the caravan tugging you back like with the standard controller. This is the most notable difference other than emergency braking.
Emergency braking
Emergency braking is where the standard controller really falls down. With a standard controller, as soon as you touch the brake pedal, the controller will start to run its procedure and will apply a predetermined brake application. In an emergency situation, like when a car pulls out in front of you, this kind of predetermined brake application is most likely not going to be perfectly matched to what the situation requires. For example, if you have the ramp set to give a gentle break introduction, this will not apply enough of a braking effort early in the emergency situation. Alternatively, if the gain is not set high enough, the caravan will not brake hard enough and will push the tow vehicle from behind during the emergency braking. In most cases, the settings will likely not be ideal, and a less than ideal brake application will be the result. Not what you want in an emergency.
The intelligent controller on the other hand will adjust the braking effort automatically based on the sudden change in motion of the tow vehicle. The controller will instantly change its braking procedure to match and will not allow the apply the brakes instantly. No lag, and just the right amount of braking effort. This will give a much better response for an emergency. In my opinion, this fact alone is worth spending the money on the intelligent controllers (not that there is much difference in pricing).
That about wraps up our comparison of brake controllers. We would love to hear your experience with controllers and when they have and have not worked well. Leave us a comment below and share your experience.
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