No there is not breakaway or battery.
Consider hooking one up. Hopefully you will never need it, but its nice when sh*t happens.
As for the brakes, pretty much all of them work the same way. You have a thick plate on the brake drum around the hub. There is an electromagnet that rubs lightly on that plate. Its mounted on an arm that actuates the brakes like the wheel cylinder on a hydraulic drum brake.
As you put power to the magnet, it gets dragged around by the wheel turning. The more power, the harder it gets dragged and the more braking.
Usually they adjust with a spoon exactly like regular drum brakes.
Now, controllers:
Here is where it gets interesting. On the surface, it seems simple. Just apply more current the harder the braking is needed. But, how to determine how much to supply?
Everybody has a "better" idea. The first controller I bought for my travel trailer, the one I still use, actually had a piece of brake line that was supposed to be spliced into the output of the master cylinder.
I hated that idea, and never hooked it up. Since I only tow twice a year, I lay the controller on the front seat, and actuate it with the manual lever when I need braking. Whatever type you get, make darn sure that you can use the manual part easily. Its important to be able to apply the trailer brakes only in many circumstances.
Other controllers have a weight inside mounted on an arm that is free to swing against a spring. The spring tension is adjustable. When you begin to brake, the weight swings forward and applies the trailer brakes.
The harder you brake, the more the weight swings and the more trailer brakes you get.
Others are hooked to the brake lights. When the brake lights come on, the controller begins to gradually apply the brakes. The ramp up rate is adjustable. The longer you have the brake lights on, the more trailer brakes you get.
When you turn off the brake lights, the trailer brakes release.
The downside to that, is if you are easing into a gas station or doing some slow moving while gently riding the brakes, eventually you will either be unable to move or will be dragging the trailer.
You have to remember to release the brakes for a second every so often.
As to which controller is best, its hard to say. Check with folks here who have the different types and get their ideas.
As for the manual part, if you are going down hill on a slippery road, you can apply the trailer brakes only to slow you down with little chance of jackknifing.
And its really nice if your trailer starts swaying due to wind or whatever.
You simply apply the trailer brakes and give the truck gas. That stretches the system right out and stops the sway.
