What is the difference between electric brakes and surge brakes?

In today’s blog post, we will answer the following question: What is the difference between electric brakes and surge brakes? We will explain how both electric brakes and surge brakes function and the main differences between them. 

What is the difference between electric brakes and surge brakes?

The main difference between electric brakes and surge brakes is in the mechanism that activates them. 

  • Surge brakes are activated by a mechanical chain that is connected to the towing vehicle and that activates the master cylinder;
  • Electric brakes have a battery-operated activation that feeds the electromagnets in the wheels. Electric brakes need a battery, an emergency switch and a brake controller to function. 

To better understand the differences between electric brakes and surge brakes, we will explain how they work in the next section. 

How do surge brakes work?

Many trailers, caravans, boat carriers and horse trailers are equipped with surge brakes. It is a very simple and unsophisticated, but very effective brake system.

The principle of the surge brake is simple. If the vehicle slows down or brakes, then the trailer, caravan, boat carrier or horse trailer moves forward. This is called inertia. The overrun brake is activated to prevent the towing unit from maintaining too high a speed relative to the car due to its mass. 

On the drawbar, there is a sliding part near the hitch / towed element coupling. This slides as soon as the towed element becomes inert. The brake cables are then pulled, and the brake linings are pushed against the inside of the drum. This mechanism then allows the trailer, caravan, boat carrier or horse-drawn van to be braked. 

The greater the thrust exerted, the greater the braking power. If the vehicle stops braking, the brakes on the object you are towing will stop being applied. If the surge brake is properly adjusted, you will not notice the braking of the object towed by your vehicle during your journey. However, try to avoid hard braking as much as possible and brake gradually as much as possible.

What is an inertia damper? To prevent when you decelerate, or during small braking, the surge brake is activated immediately, and an inertia damper (a shock absorber) is installed. Several types of shock absorbers are available, depending on the mass of the caravan. The heavier the trailer, caravan, boat carrier or horse trailer, the more effective the shock absorber must be. 

You can control the operation of the shock absorber by activating the trailer brake (unhitched), pushing in the slider with your hand, and then removing it. There must be strong resistance.

When reversing, the trailer, caravan, boat carrier, or horse-drawn trailer also exerts pressure against your car. To prevent the activation of the surge brake, an automatic recoil recognition system has been incorporated into the brake drums. This system also ensures that the trailer can back up another half a meter when you put the towed component into the handbrake. So never unhitch your caravan on a slope in reverse.

When descending, on mountain roads, a surge brake has restrictions. If you go down a particularly steep hill at a constant speed (using the engine brake), the trailer will push against your car, causing your trailer to brake constantly. The consequence is that the brakes of your caravan can overheat. The best thing to do is to stop regularly and let the brakes cool.

How do electric brakes work?

Like all electronic systems, the electric handbrake has advantages and disadvantages, which are more or less compatible with drivers’ expectations.

An electric brake acts on the wheels in exactly the same way as a mechanical brake system. In fact, the difference between these two devices is in their operation. Electronic assistance quite simply automates manual actions. Its mission is to determine the best action to take to deal with a situation. To achieve this, various sensors are positioned on the vehicle in order to transmit data to a computer. 

For example, this may involve detecting that the vehicle is stationary to engage in “parking” mode. When starting on a hill, the same sensor is associated with ABS, and when backing up is detected, the wheels are locked.

One of the main advantages of electric brakes is removing obsolete mechanical parts, the wear and tear of which required regular maintenance. By automating this system, automakers have been able to increase its scope. Finally, the installation of a computer makes it easier to analyze and detect any malfunctions.

The more powerful an electronic system, the more complex the repairs become. When it comes to the electric handbrake, diagnosing and making the necessary repairs is no longer accessible to amateur mechanics. 

Also, the slightest anomaly requires the intervention of professionals, which significantly impacts the number of repair costs. In some cases, breakdowns are recurring and end up undermining the confidence of vehicle owners.

What type of brakes do trailers have?

Let’s start with the fact that not all trailers have brakes! Most trailers have either surge brakes or electric brakes. In fact, in most states in the US, the law doesn’t require brakes if the trailer weighs less than 3000 lbs.

Most states require trailers equipped with electric brakes to have a safety circuit called a breakaway system that applies the brakes when the trailer is disconnected from the tow car. This system consists of a trailer-mounted battery and a normally closed switch.

The key contacts exist separated by a non-conductive plastic piece to which a loop is attached. 

The other end of the cable is connected to the towing vehicle. The loop pulls the plastic spacer away from the key contacts when the trailer is separated from the tow vehicle. The button closes and applies power from the onboard battery to the brakes, stopping the trailer.

Consider getting a braked caravan on heavier trailers and caravans, which exceed half of the vehicle towing unladen. Its role is to assist the vehicle’s primary braking and relieve it of the trailer’s weight.

The goal is to reduce the braking distance to ensure better passenger safety. But it also makes it possible to extend the life of the towing vehicle’s brakes and the trailer’s contents.

Braked trailers are attracting more and more motorists because of the convenience they offer. Not to mention the additional volume they offer to transfer large materials. Whether you should choose trailers with or without brakes depends on the conditions of use and the driver’s needs. Also, many companies market these trailers in equally different formats.

These trailers vary in size, width, length, the material used, and we go. And the selection criteria are more and more numerous today. What interests us here is rather whether it is braked or not.

As the name suggests, a trailer that benefits from this device is a trailer that has its brake mechanism. However, keep in mind that it is not enough on its own to guarantee the trailer’s good handling. Whether in autonomy, or once hooked up to a towing vehicle. The brakes used are very often drum brakes. They rest on jaws, which come to rest on the drum and thus slow down the wheel’s movement until it stops.

The bottom line

When selecting the type of brakes for your trailer, caravan or boat, think about how often you will use the vehicle itself. Electric brakes are more reliable, easy to install and use; however, they do require an electric controller to work.

On the other hand, Surge brakes function on a passive system that doesn’t need any electricity or particular installation to work. They are, nonetheless, much more difficult to understand and repair. 

What would you choose? Please let us know if you have any questions or comments on the content!

FAQ on What is the difference between electric brakes and surge brakes?

When does my trailer need brakes? 

As a general rule, the need for a trailer with a separate brake system depends on its weight. Most states require your trailer to stop if it exceeds 1000 pounds. However, many require all trailers to be braked regardless of weight, so your best bet is to do some research and research what works best for your trailer and the conditions you live in.

What if my trailer brakes fail? 

Usually, there are too many protective measures that brake systems bring to avoid some substantial disaster. Therefore, the complete and complete destruction of your brakes is as little as possible. However, if your trailer appears to have a will of its own, it will keep moving when you stop and hit the rear of the truck. It can also keep you moving, especially when the road is slippery. But as long as everything is configured correctly, it is very rare.

Can I tow a trailer with electric brakes without a brake controller?

No, you cannot tow a trailer with electric brakes without a brake controller, as it would be useless. Electric brakes need a brake controller to work!

How much does it cost to install electric brakes?

The average cost to install electric brakes is $500, if done by a professional. The costs can be a lot less if you decide to install them yourself. 


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