1. Trailer Breakaway Kit
  2. Curt
  3. Kit with Charger
  4. Battery Included
  5. Side-Load
Curt Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger - Side Load

Curt Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger - Side Load

Item # C52042
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A push-button tester with LED indicator lights makes it easy to know if this breakaway system's battery is fully charged so you'll have peace of mind while towing. The built-in charger refuels the gel cell battery without overcharging. Lowest Prices for the best trailer breakaway kit from Curt. Curt Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger - Side Load part number C52042 can be ordered online at etrailer.com or call 800-298-8924 for expert service.
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Curt Trailer Breakaway Kit - C52042

  • Kit with Charger
  • Curt
  • Battery Included
  • Side-Load

A push-button tester with LED indicator lights makes it easy to know if this breakaway system's battery is fully charged so you'll have peace of mind while towing. The built-in charger refuels the gel cell battery without overcharging.


  • Breakaway system activates your trailer's electric brakes if the trailer disconnects from the tow vehicle
  • Push-to-test battery case offers fast and easy battery testing
    • Press the button on the lid and hold for 3 seconds to test
    • LED lights on lid clearly indicate the status of the battery
      • Green = charged
      • Orange = charging
      • Red = low battery
  • Built-in charger automatically refuels the battery
    • Fully charges the battery without overcharging
    • Trickle charge maintains voltage while you tow
  • Side-loading case is easy to access from the side
    • Weather-resistant polyethylene construction protects the battery and charger from moisture and debris
    • Self-tapping screws included for simple mounting on your trailer's frame
  • Lockable lid deters theft
    • Fastens using (4) 1/2" x 2-1/2" screws (not included)
    • Locks using a padlock (sold separately)
  • Breakaway switch installs on your trailer's frame - drilling is required
  • Department of Transportation (DOT) compliant
  • 12V gel cell battery is included


  • Application: 1 to 3 axle trailers with electric brakes
  • Battery capacity: 5 amp-hours
  • 1-Year limited warranty

Note: A breakaway system is required by law in most states for trailers that are equipped with electric brakes and have a GTW of at least 3,000 lbs.

52042 Curt Side Load Push-to-Test Break Away System with Lockable Box

C52042 Installation InstructionsInstallation Details C52042 Installation instructions

California residents: click here

Video of Curt Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger - Side Load

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Curt Push-To-Test Trailer Breakaway Kit Review

Speaker 1: Today we're going to be taking a look at the Curt Side Loading Push to Test Trailer Breakaway Kit with built in battery charger, part number C52042. Here's what our breakaway system looks like. Now, in a lot of states, it is a requirement to have a breakaway system if your trailer weighs over a certain amount and you have electric breaks on it. We're going to have a tethered cable that's going to be attached to our towed vehicle that's also going to be attached to the plunger on our breakaway switch and in the event that our trailer does come uncoupled, it would pull this plunger out, which then applies the breaks to our trailer.Our breakaway system is going to have a built in battery, so we're going to make sure that we have power to apply to the brakes. Now, the nice thing is, is it's also going to have a built in charger, and the wire's going to charge from the 12 volt power source at our trailer connector. If we come to the top of the box here, we're going to have this button that we can push to test our battery.

If we push it, we can see we get a green light, which is going to let us know that the battery is fully charged.Whenever we have it hooked up to our tow vehicle, we can see that we get an orange light letting us know that it is charging. The nice thing is it has a trickle charge in it, so it's not going to overcharge our battery. It's just going to charge it just enough to maintain the voltage whenever we are towing our trailer. Now, since the battery is already charged I'm not going to be able to show you, but on the other side where our three LEDs are, if the battery we're to get low, we would have a red light whenever we push the button to test it.To demonstrate how our breakaway is going to work, we're going down the road and our tires are spinning, but in the event that our trailer comes uncoupled and that pin is pulled, it's going to lock up the brakes and stop our trailer. Like most breakaway systems, it is going to include that 12 volt battery, as well as a charger that's built in and a way to check the battery before we tow.

The nice thing about our Curt is that it does work with trailers from one to three axles with electric brakes.Our tether's going to be 4 feet long, so we're going to have plenty of length to connect to our towed vehicle. Our Curt breakaway kit does meet the Department of Transportation guidelines. Now that we've seen how our breakaway system works and gone over some of the features, let's show you how to get it installed.To begin our installation, we're going to need to find a spot to mount our battery box. Now, we're going to have a couple different options of how we can mount it. We can take the four provided screws and we can go through the large opening here and drill it into our frame.

However, if we do that we're not going to have access to open up the battery box without removing the screws.If we take the cover off and we look on the inside, we'll notice that we're going to have four indentions on the inside. Instead of doing that, using the long screws provided in our kit, we're going to grab four self tapping screws and drill a hole through the battery box itself and use those to mount onto the frame. Now, these self tapping screws don't come in the kit, but you can pick them up on our website at etrailer.com.Using a 5/16 nut driver, I'm going to run the self tapper through the plastic first so I can see where the hole's going to come out. I'll do that for all four locations. Now we're going to want to find a suitable spot on our frame.

Want to make sure your wires are out of the way so they're not going to get crushed, and we can go ahead and take our self tapper and drill right into our frame. If you're having trouble getting the self tappers going through the frame, you can start out with a small drill bit and pre-drill all the holes. With one of the self tappers in place, I'm going to come back with a marker and I'm going to mark the other three holes so I can pre-drill those and make sure it doesn't move.With all the holes pre-drilled, we install the self tapping screws and secure the battery box to the frame. We can get ready to mount our breakaway switch itself. Now, on our trailer we already had a stud that's welded to the frame, so we can use that to mount it. However, you don't have a spot, they do provide you with a couple self tapping screws to get it in place. We're going to slide ours over the stud, install the nut. You want to make sure that the end with the tether on it and the plug is facing towards the front of the trailer.With all of our components in place, we can begin to start making our electrical connections. We can grab our battery and we're going to remove the plastic covers that are on the terminals. Now, on the positive post of our battery, which is going to be the red terminal, we're going to take the tap that they provide in our kit, and that's going to give us two locations that we could hook onto.We're going to take it and with the two terminals pointing out towards the collar on the battery, like this, we're going to slide the tap onto the post of the battery, make sure it locks into place and it's not going to fall off. I'm going to get my battery close to my battery box so that we can make our connections for our charger inside. The red cable is going to go to one of the posts on our positive side. We can just slide it over, make sure it's secure. Then our black cable is going to go to the negative side of our battery. Again, just going to slide it onto the post, making sure that it has a good connection.Now, the reason why we needed that second post on that tap is because on our breakaway switch, we're going to have two black wires and one of them is going to have a pre-installed spade terminal, just like on our charger. We're going to reach down and we're going to plug it into the other side on the positive side of the battery. Now, since this wire does have to go inside the box, I'm actually going to cut a small slit in the grommet so I can pass my wire through, and it'll be all protected and it won't be chafing on the edge of the box here.Whenever you do cut the grommet, you want to be extra careful not to cut the wires that are coming out of it. Just going to make a small cut, and we can pass the black wire coming from our breakaway switch inside the grommet. We can take our battery and we can put it inside of our battery box, making sure all of the wires are going to get tucked in neatly and not get crushed or interfere with the lid going on. Then we can take our lid and we can close up. Just want to try to get that grommet to go around the lid as well, so we have a nice seal to keep any kind of moisture and debris out. Make sure the wire's on the inside of that grommet.Now, to secure our lid I'm going to take some screws and I'm going to go through the small tabs on the corners here, passing them through and then securing them down with a hex nut. We'll just get them all in place by hand, and then we can come back with a wrench and a screwdriver and tighten everything up. I do want to mention that these screws and nuts don't come with the kit, but you can pick them up at your local hardware store. Just want to make sure you get some that will fit through these tabs here on the corner. Since we did have to cut that grommet, I'm going to come back with some black silicone and seal up that spot, keeping out any kind of moisture or debris from getting inside the circuits.We're going to have three wires left. One more black wire coming from our breakaway switch itself, a yellow wire, and a white wire with a ring terminal coming out of our battery box. All three of these are going to have to go to our trailer junction box to where we can make our connections. We can go ahead and remove the cover and get our wires inside. We're going to pass our three wires through the grommet that's going into our junction box. If you can, it probably would be easier to just pull the grommet out, give yourself a little bit more room to work. Then slide the wire in. You want to make sure you get all three wires; the black one, the yellow one, and the white one into the junction box. We'll then pull the slack through and we can put the grommet back in place.Now we'll go ahead and start with our black wire. Our black wire coming from our breakaway switch is going to need to go to our trailer brake circuit that's in our junction box. Now, most likely it's going to be connected to a blue wire, but in our case our color codes aren't correct, so we're going to need to find our brake signal, which we know is over here. We're going to estimate about how much wire we need and cut the wire back. Strip back the end of it, and we're going to attach a small ring terminal, which these aren't included in our kit but you can pick them up on our website at etrailer.com. Crimp our ring terminal in place, then we're going to remove the nut on our brake terminal and pass our wire over, slide it over the terminal, and replace the star washer and nut.Now, our yellow wire is going to go to our 12 volt power source in our junction box. It's going to be this terminal here with our black wire that's going out to our trailer connector. Again, just going to estimate about how much wire we need and trim it back, strip back the end of it, and we'll do the same thing we did with the other one. Our white wire's going to need to go to our ground terminal, which is going to be right here. We can remove the nut and do the same thing attaching it. Just want to make sure that you route the wire so it's not going to interfere or rub on any of the other terminals, so you may want to just tuck it up out of the way. Then we can replace the cover on our junction box.Now we've gone and cleaned up all the loose wires that we have leftover. To clean up all our wires I took some wire loom, some zip ties, and som electrical tape to help protect it and to keep everything nice and neat here in the frame rail. Now all we have left to do is to check the battery to make sure it's charged. If we push the button on the top, see that it gives us a green light so we know the battery's charged and we're ready to hit the road. That'll finish up your look at the Curt Side Loading Push to Test Trailer Breakaway Kit with built in battery charger, part number C52042.

Customer Reviews

Curt Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger - Side Load - C52042

Average Customer Rating:  4.5 out of 5 stars   (16 Customer Reviews)

A push-button tester with LED indicator lights makes it easy to know if this breakaway system's battery is fully charged so you'll have peace of mind while towing. The built-in charger refuels the gel cell battery without overcharging.

- C52042

really great product, easy to install, I added a junction box form you made the brake away easier better looking install. I recommend it to anyone! 615890

- C52042

received as ordered, just what I needed 335961

- C52042

Very good product. Don’t want to see a trailer with thin enough steel that the mounting screws would actually work. Did have a bit of a hard time mounting since the bolt spacing was pretty wide, but got it to work. Kit is complete, works very well, and was relatively simple to install. Recommend it for the money. 642026

- C52042

Easy to install, drill 3 holes, hook up wires, done. Works great when tested, instructions were clear enough for even me. 485293

Not well. I dont know if I wired it wrong or what, but the battery died. Everything checks out ok with a multimeter except the dead battery.
Larry - 03/18/2019


If the vehicle 7-way that you are using this with does not have a powered 12-volt connection to help maintain the battery then that may be the issue. If not then check out the installation instructions and refer to page 2 for additional info.

-- Rachael H - 3/21/2019

- C52042

Arrived quicker than expected. Seems to be high quality. Have not had time to install, so I cannot address the difficulty of installation or the performance. 580658

- C52042

Exactly what I needed. Etrailer had the best price. Quick shipping. 243192

- C52042

Easy to install. Great safety feature for my horse trailer. I usually haul my RZR in it. 549320

- C52042

Replaced a outside rail unit on my Trailex enclosed (1999) with this unit, but moved it inside by winch mount to better protect from elements. 1 year in, start of new towing season, still working as designed (brake engage), charging off of tow vehicle 12v power from 7-pin cable source. Would buy again to replace a dead battery, to all new accessories, not a place to scrimp. 258608

- C52042

Kit showed up on time, installed easy and functioned perfectly. 698787

- C52042

This was easy to install and nothing else was needed. Great features and makes pre check of the trailer easy. 668255

- C52042

The screws it comes with to hold the case shut aren’t large enough. Minor issue 666839

- C52042

Quality is outstanding...haven't installed yet. Great company and customer service. Will leave later review after use. 641914

- C52042

Excellent Break-a-way kit ! 599814

- C52042

fast shipping 578460

- C52042

The best. And perfect. Fit. Thanks 435896

- C52042

Good product but direction and diagram lacks the clarity to cover all types of installation. 389883


Ask the Experts about this Curt Trailer Breakaway Kit

  • Is There a Curt Soft Trac Breakaway Kit that Has Battery Charge Indicator
    If you are looking for a similar trailer breakaway kit that has a built in charger and tester we have the Curt part # C52042 which will show you when it's charging and charged but the part # C52040 that you referenced does not have this feature.
    view full answer...
  • Where to Attach Cable for Curt Push-To-Test Trailer Breakaway Kit
    The most common method for attaching the cable for a breakaway kit like the Curt Push-To-Test # C52042 that you referenced is feeding it through the safety chain loop on the trailer hitch. The warning message that you mentioned on the instructions manual caught me a little off guard so I called my contact at Curt and he actually said that "mounting hooks" in that statement refer to the hooks on the safety chains themselves. He said that the cable can absolutely be connected to the tow...
    view full answer...
  • Comparing Trailer Breakaway Switch Kits
    Some different brand names of trailer breakaway kits do originate from a common source, and this is also true for items like jacks, landing gear and steps. There really is not a lot to distinguish one from another, since their component parts are virtually identical: a battery, a box, a charger and a switch. The one part that can make a difference is the battery itself. A higher output battery can power brakes on more axles. Hopkins Engager Trailer BreakAway Kit # 20400 can handle 1 or...
    view full answer...
  • Best Breakaway Kit with Push To Test Feature for Triple Axle Trailer
    I do have an option for you but the Hopkins Engager Push-To-Test Trailer Breakaway Kit w/ Built-In Charger part # 20099 is only rated for use on single and tandem axle trailers. For a breakaway kit that is rated for use on triple axle trailers you will want to use the Curt Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger part # C52042. The Curt breakaway kit as the title suggests also has a built-in push to test feature as well as a side load battery box just like the Hopkins...
    view full answer...
  • How To Move A Trailer With A Dead Breakaway Battery
    On most breakaway kits such as the Hopkins Brake Master part # HM20001, you will not need to cut or splice any of the wires to move the trailer with a dead battery. If your power supply is not active, then the only effect is that the breakaway system will not send power to your trailer's brakes in a breakaway situation thus allowing for free movement of the trailer. Even if the battery is dead, the brake controller will still allow you to activate your trailer's brakes To prevent further...
    view full answer...
  • Does Charging Battery of Curt Breakaway Kit # C52042 Take a Long Time
    To charge a battery through the 12 volt accessory circuit of a vehicle and trailer wiring does take some time. If the battery was in a pretty low state of discharge it would not surprise me that it's still charging. If you wanted to charge the battery quickly you'd need a charger that plugs into a wall outlet like the part # CTEK56353.
    view full answer...
  • Could One Trailer Breakaway Kit be Used on Several Fifth Wheel Trailers
    Breakaway kits aren't really designed to move from trailer to trailer easily. They are designed for a permanent install. Since nearly all areas will require a breakaway kit to be installed on the trailer the best solution would be to install a breakaway kit like the part # C52042 on all of the trailers. It'll also save you a lot of time trying to swap the kits each time you have to tow a different vehicle.
    view full answer...

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Info for this part was:

Edited by:
Lindsey S
Installed by:
Jeff D
Installed by:
Cole B
Installed by:
Robert C
Expert Research:
Jameson C
Video Edited:
Kathleen M
Written by:
Chelsea B
Updated by:
Kristina F
Updated by:
Isabelle B

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