1. Trailer Breakaway Kit
  2. Hopkins
  3. Kit with Charger
  4. Top Load
Hopkins Engager Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger - Top Load

Hopkins Engager Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger - Top Load

Item # 20400
lowest price pledge
Retail:$79.47
Our Price: $45.43
You Save: 43%
Trailer Breakaway Kit
Orders above $99 qualify for Free Shipping
Shipping Weight: 4 lbs
Quantity: 
In Stock
20400 - Top Load Hopkins Kit with Charger
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

In Use/Installed

Customer Photos

Breakaway system with built-in charger is designed to bring a trailer safely to a stop by activating its electric brakes should it become disconnected while being towed. Push-button tester lets you know if the rechargeable battery is fully charged. Lowest Prices for the best trailer breakaway kit from Hopkins. Hopkins Engager Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger - Top Load part number 20400 can be ordered online at etrailer.com or call 800-298-8924 for expert service.
  • All Info
  • Reviews (364)
  • Q & A (85)
  • Photos
  • Used (1)
  • Why etrailer?

Hopkins Trailer Breakaway Kit - 20400

  • Kit with Charger
  • Hopkins
  • Top Load

Breakaway system with built-in charger is designed to bring a trailer safely to a stop by activating its electric brakes should it become disconnected while being towed. Push-button tester lets you know if the rechargeable battery is fully charged.


Features:

  • Breakaway system activates your trailer's electric brakes if the trailer disconnects from the tow vehicle
  • Push-to-test battery feature offers fast and easy battery testing
    • Test button with LED lights clearly displays battery status
      • Green = charged
      • Yellow = charging
      • Red = low battery
  • Built-in charger automatically refuels battery while trailer is connected to tow vehicle
    • Charges at 1/2 volt below voltage supplied by tow vehicle to prevent over-charging
    • Shut-off feature activates when battery is fully charged
  • Top-loading case is easy to access from above
    • Weather-resistant construction protects battery from moisture and debris
    • Self-tapping screws included for simple mounting on your trailer's frame
  • Lockable lid deters theft (padlock sold separately)
  • Breakaway switch installs on your trailer's frame - drilling is required
  • Department of Transportation (DOT) compliant
  • 12-Volt rechargeable battery is included


Specs:

  • Application: single- and tandem-axle trailers with electric brakes
  • Case dimensions: 4" long x 8" wide x 6-1/4" tall
  • Battery capacity: 5 amp-hours
  • Mounting hole spacing:
    • 7" From center of hole to center of hole horizontally
    • 1-1/2" From center of hole to center of hole vertically
  • 16-Gauge wires
  • 90-Day 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.



20400 Hopkins Engager Push-To-Test Trailer Breakaway Kit with Built-In Charger - Top Load - 5 amp/hrs

Installation Details 20400 Installation instructions


California residents: click here



Customer Reviews

Hopkins Engager Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger - Top Load - 20400

Average Customer Rating:  4.8 out of 5 stars   (364 Customer Reviews)

Breakaway system with built-in charger is designed to bring a trailer safely to a stop by activating its electric brakes should it become disconnected while being towed. Push-button tester lets you know if the rechargeable battery is fully charged.

- 20400
by:

Since I was rewiring the trailer anyway, I decided to install the breakaway as an upgrade. I received the part in good shape and it appears to fill the bill. I mounted the switch in the front of the V of the hitch where there is a flat surface. I drilled a 3/4" hole to allow the pin to be inserted without being subjected to damage. The mounting surface used was a plate along side of the jack lift. By mounting it against the backside of the front plate through the hole, the switch is held in place and totally protected. I mounted the battery in the upper part of the storage compartment in the front of the trailer and used a terminal strip to connect it to the other wiring as needed. I connected the interior LED lights through a switch to this battery to provide lighting inside the trailer. Pretty cool. When the vehicle is connected to the trailer, the battery is charged. If the pin is pulled out of the breakaway switch, the power from the battery is applied to the brakes. The battery is quite small something like 4 amp hours, but that is great plenty to operate the brakes in any emergency situation for several minutes because the brakes have a small draw. The only problem I had with the battery was that it lays in the package without constraints so that it can flop around. It had yanked the white wire loose from the battery so the system did not operate until I realized that it was disconnected. So I reconnected it and put it back together, but the wire disconnected again. The wires pass through a slot in the box and are also not constrained so that they are pulled out by operating the cover door. I just taped the wires together with electricians tape so they fit more firmly in the slot provided. 652885


Comments
The only problems I have encountered are 1 the battery continues to run down. It is difficult to keep it charged up. 2 The pin comes out too easily, and unfortunately I cannot tell it because the brakes wont hold well enough. 3Thats it! The item works fine - it is a big asset to the trailer.
James W - 06/05/2020

78835

- 20400
by:

Good experience. Fast shipping easy ord ering 889549



- 20400
by:

Great product. Easy to install. 881580



- 20400
by:

Excellent Customer service, fast delivery and great/helpful people. Highly recommended 876981



- 20400
by:

Haven't installed it yet, but it's just what I ordered. I ordered a receiver hitch and a bick rack for our Subaru a fue years ago works great! etrailer is a great company. 850728



- 20400
by:

I really enjoy purchasing items through etrailer, they always have items that I need and quick to deliver product. 849564



- 20400
by:

Great service fast delivery product installed easy 821098



- 20400
by:

I spent a lot of time looking at and for an emergency trailer brake. I loved the etrailer website, it showed me good, better, best and clearly and quickly told me the costs and the difference between each. My unit arrived sooner than expected, in excellent shape, and included a battery which was a surprise! I have not installed it yet, but I am sure it will work great and do exactly what I need it to do. I have ordered from etrailer before and have never been anything but happy with my products. 816191



- 20400
by:

Thanks to the folks at etrailer, I chose this Hopkins e-brake kit with charger. It came exactly as advertised, quickly and was a pleasure to install. It is a perfect fit for the Hopkins 7-pin wiring harness I recently installed. Having both of these items from etrailer allowed me to get my trailer brakes back in working order and now I know the trailer is reliable and safe to hit the road. Great website, products and support team! 812288



- 20400
by:

Everything I have purchased from you had been the highest of quality. Very quick delivery. I rebuilt my boat trailer with your part and I couldn't be happier 807516



- 20400
by:

Easy install if you are somewhat mechanically inclined. buy it you will like it. 805889



- 20400
by:

Thanks for the great service 803196



- 20400
by:

Easy to install. I like the test button so I know that the brakes will work if I ever have a disconnect. 799715



- 20400
by:

I bought these brake batteries when rewiring two old horse trailers. This is the third & fourth trailer I've rewired, so I'm pretty used to it by now. Everything about this product went together easily. Routing the wires on the trailer was another story, as usual. I sold one trailer, but I've been using the other trailer infrequently for about a year now, and the brakes seem to be working quite well. I haven't had an occasion to test the breakaway battery out on the road, fortunately, but the little lights on the top indicate that it's maintaining a good charge, and the breakaway switch did lock up the brakes when I tested it in my shop. BTW, I *love* pairing these with the Bargman coiled wiring plugs. They're so much nicer to use than straight wires. 797825



- 20400
by:

Good quality. Perfect to replace an old non working breakaway battery. 789972



- 20400
by:

good parts quick service ease of instal lation 786639



- 20400
by:

Great pricing super fast shipping the staff is very helpful and knowledgeable would highly recommend for all your trailer, wiring and towing needs 782573



- 20400
by:

Another good purchase. I have no complaints now nor ever have had. I highly recommend etrailer. 766223



- 20400
by:

I ordered a number of items for a trailer that I am bringing back to life after leaving is stand at the beach for nearly 12 years. I got great advice on what parts I needed to match the original Haulmark lights and license plate bracket/light and also ordered a new breakaway system and safety chains. Everything was priced reasonably, shipped in a timely fashion and was a cinch to install as it all fit right to the original footprints. I also found answers to my questions on some electrical issues by browsing the Q&A sections here. Happy customer. 756638



- 20400
by:

Fixed us right up..extremely happy with purchase...exactly what we needed 749610



- 20400
by:

Great service , had a problem with a product that was handled very fast !!!!!! 747616



- 20400
by:

Quick processing, and delivery. reasonably priced . Adding this to my enclosed 16' trailer. Plan to mount it inside to keep it safe and secure. Impressed that it came fully charged. etrailer is my initial go to source for any trailer / motorhome /ATV related purchases. Great selection of parts and tons of how - to videos . Thank you for everything. 747295



- 20400
by:

Like how easy it was to install the hitch, and breakaway switch, however, the only logical way to hook the wires up results in the blue wire from battery box connecting to black wire of switch. 746735



- 20400
by:

This company has a great selection of parts and the shipping is always extremely fast. I have ordered from them in the past and will continue in the future. The how to video's are also very helpful. 746060



- 20400
by:

Because I just received my product, what I am really reviewing is the process for selecting it and the customer service I received. First, my order came very quickly. The part of the process that I appreciated the most was the videos available with each part to show installation. They made it very easy to know that I was ordering exactly what I needed. 745079


25
365
Show More Reviews

Ask the Experts about this Hopkins Trailer Breakaway Kit

  • Will The Breakaway Switch Draw Power When Disconnected From Tow Vehicle
    When you unhook the trailer from the SUV you are not going to pull the pin of the breakaway switch to activate the trailer brakes. The only time the breakaway switch is going to pull power is if the pin is pulled from the breakaway switch which activates the brakes. The other side of your breakaway switch has a cable that attaches to the vehicle's frame or hitch while towing. Most people use a clip to attach the loop at the end of the cable to the vehicle's frame or loop it through the...
    view full answer...
  • Can Breakaway Switch By Itself Be Used If Trailer Already Had Battery
    If you have a battery already on your trailer that's getting a charge and would be adequate to hold the brakes of your trailer in the event of a breakaway you could wire just a switch from it to your brake output circuit and you'd be fine. For that you'd only need a switch like the # FA80-00-2040 for a kit with a coiled cable or part # 2005-P for a kit with a straight cable. The battery setups like the part # 20099 would only be needed if you also needed a battery to power the system.
    view full answer...
  • Electric Trailer Brakes Engaging
    Thanks for the nice words and all that information! It certainly isn't normal that your trailer brakes are engaging without a brake controller though there are a couple of reasons why this can happen. My guess is a wiring issue on the trailer where the wires are making contact and 12 volt power is getting through to the brakes. So I recommend going over the wiring from your brakes and tracing it to see if there is an issue there. If need be you can replace with 10 gauge wire # 10-1-1. Or...
    view full answer...
  • How To Wire Up Hopkins Engager Push-To-Test Trailer Breakaway Kit
    In regards to the Hopkins Engager Push-To-Test Trailer Breakaway Kit part # 20400, there are only two wires with the black being power so it should be run to the positive battery terminal and the blue being brake output so it should be run to the brake output circuit. I have attached a wiring diagram you should use below.
    view full answer...
  • Installation of Breakaway Kit Switch for Electric Trailer Brakes on Gooseneck Trailer
    Hopkins Engager Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger - Top Load # 20400 can have the pin mounted on the coupler. The angle should be as aligned as possible with the point you are connecting to and be slightly shorter distance than your safety chains. The pin will pull with force so the pin is designed to withstand that without breaking as is the cable. The length and angle are important because you want the trailer brakes to activate when the trailer becomes...
    view full answer...
  • Mounting the Hopkins Engager Push-To-Test Trailer Breakaway Kit on Horse Trailer
    It's pretty easy to mount the Hopkins Engager Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger # 20400 on your horse trailer; the kit actually comes with self-tapping screws so you simply need to use those to mount it on an available space on your trailer. If you are having trouble finding an area to mount the kit you can also use the Weld-on Trailer Frame Mounting Plate for Hopkins Engager Breakaway Kit # HM20407 which you can weld onto your trailer frame to mount the...
    view full answer...
  • Power Draw On Tow Vehicle Battery to Charge Hopkins Engager Push-To-Test Trailer Breakaway Battery
    The Hopkins Engager Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger part # 20400 has a maximum power amp draw of 2 amps to charge the breakaway battery. The power draw is so low is will not drain the tow vehicle's battery. It will also only charge when the trailer is connected to the tow vehicle and the 12V circuit is active. On some vehicle's that does require the ignition to be turned on.
    view full answer...
  • Testing Vehicle 7-Way for 12V Power Signal for Charging Breakaway Battery
    Some vehicle's 7-way will have a 12V power circuit that remains active at all times (even with the key off) while others will have this circuit off unless the key is in the accessory position or the engine is running. This is not consistent between auto makers nor vehicle models. If an aftermarket 7-way was added to a vehicle it could have been set up either way. If you have a circuit tester like # PTW2992 you can test your specific vehicle to see under what conditions that 12V auxiliary...
    view full answer...
  • Trailer Breakaway System Operation And Troubleshooting
    The brakes shouldn't necessarily lock up, but the brakes should quickly bring the trailer to a safe stop. The weight of the trailer shouldn't matter if the breakaway kit and the trailer brakes are working properly. All trailer from utility to RV with a much larger weight capacity than the 5,000 lbs you mentioned use breakaways like the Hopkins # 20400. If it isn't functioning to a safe level, there is a need to fix something. It may be a ground, it may be a brake magnet, it may...
    view full answer...
  • Trailer Breakaway Kit Recommendation with 9 amp Hour Battery
    We don't have a 9 amp hour battery to swap into the battery box of the Engager but I do have a great solution for you. The Dexter Breakaway Kit part # 34-285 is a kit that comes with a 9 amp hour batter and a box large enough to fit the battery size.
    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...
  • How to Tell If Your Breakaway Switch Is Powered By Trailer Battery or Auxiliary Battery
    If you already have a breakaway switch and trying to find its power source, It is possible that someone could have wired the breakaway switch directly to the main battery on the trailer but it does not come like that from the factory. The breakaway switch should be wired to a separate battery. Most Breakaway switches come with their own battery and some come with a battery charger. The breakaway box is essentially a plastic box with a battery in it that powers the breakaway switch. When...
    view full answer...
  • How to Wire Break Away Switch on Hopkins Engager Break Away System
    The black wire from the break away switch will connect to the blue wire from the break away box, as shown in the provided diagram. By 'brake wires' I'm assuming you're speaking of the wires connected to the brake magnets on your brake assemblies. One wire exiting the brake magnet could connect to the brake output circuit, usually a blue wire and the other would ground to the trailer frame. It doesn't match which goes where.
    view full answer...
  • Wiring Diagram for Trailer Breakaway Kit
    On this page (typically below the product links) there is a helpful link section that will have the install instructions fo the Hopkins Breakaway kit part # 20400 that you referenced. I also attached an install video that shows the kit installed as well as a diagram for trailer breakaway wiring as well. The white wire is the ground wire.
    view full answer...
  • Troubleshooting Shorted Out Brake Controller Connected to Breakaway System
    I'm sorry that this happened to your brake controller. I am happy to do research to help get this issues resolved. If when testing the breakaway system and the pin was pulled with the battery connected backwards. This would compromise the brake controller. When reaching out to my contact at Tekonsha we agreed that there may be a wiring issue someplace in the breakaway system. The combination of the wiring issue, combined with pulling the pin would certainly cause frying of the brake...
    view full answer...
  • Maintaining a Breakaway Trailer Battery in a Cold Colorado Winter for 6 Months
    I recommend a battery charger like # CTEK56674 which has a cold weather mode (-4 degrees F) and you can leave it connected for extended periods of time without damaging the battery or charger. If it gets colder than minus 4 degrees then taking the battery inside to charge would be the best idea. I have included some helpful links on battery chargers for you.
    view full answer...
  • Will Hopkins Engager Push-To-Test Trailer Breakaway Kit # 20400 Get Damaged from Sun Exposure
    We have not heard complaints from customers regarding Hopkins Engager Push-To-Test Trailer Breakaway Kit # 20400 like what happened with your old system. You could limit direct exposure to the sun somewhat by using # 20099 which is designed to mount with the panel facing to the side rather than up (though it doesn't have to be mounted that way).
    view full answer...
  • Where is the Best Place to Install Engager Trailer Breakaway Kit
    The Engager Trailer BreakAway Kit # 20400 can be mounted to either a trailer's frame or jack. The recommended method is to use the weld on bracket part # HM20107. It does not come with U-bolts but it does have holes in the mounting brackets to allow it to be attached. No mounting hardware is included so you'll need to get that separately.
    view full answer...
  • Why Does Amber Light Illuminate on Hopkins Engager Push-To-Test Trailer Breakaway Kit
    The amber charging light should not be always on so you are going to want to verify that the Hopkins Engager Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger # 20400 is wired correctly. You will want to make particularly sure the ground wire is attached directly to your trailer frame. It may also be possible that somehow moisture got in the battery box and causing a short.
    view full answer...
  • Breakaway Battery Recommendation for Triple Axle Trailer
    I have a couple of breakaway battery kit options for you, but the Hopkins Engager Trailer BreakAway Kit # 20400 is not compatible with your triple axle trailer. The # 20400 is only designed for use with single and tandem axle trailers. For your triple axle trailer, you will want to use a breakaway battery that is designed to work with triple axle trailers. I recommend using the Tekonsha Push to Test Breakaway Kit with Premium Integrated Charger # 50-85-313 because it has the same great...
    view full answer...
  • Breakaway Battery Kit for Sundowner 2 Horse Trailer
    The Hopkins Engager Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger - Top Load # 20400 will absolutely work with your Sundowner 2 horse trailer. I've attached some videos to assist and have also attached the diagram and an article to assist.
    view full answer...
  • Do You Carry the Pin for Engager BrakeAway Kits / Systems?
    We do carry replacement pins for the Engager Trailer Breakaway Systems. Item HM20010 has 7inches lead wires, and item number HM20014 has 44 inches lead wires. I will link you to both items below.
    view full answer...
  • Does a Breakaway Battery that Sat for 3 Years Including Winters Need to be Replaced
    It is entirely possible that a breakaway battery that has sat for 3 years including winters could now be bad. A local auto parts store might be able to test it to see if the battery is bad or not. But If it were me I would just replace the battery with a new one that you know isn't going to have any issues. If your existing battery is 3-1/2 inches by 2-3/4 inches by 4 inches then you can use # HM20008. As a matter of fact, all of the breakaway batteries we have are this size, see link.
    view full answer...
  • Will A Breakaway Kit Operate Properly Without An Auxiliary Battery
    It is possible to operate a breakaway switch from the trailer's main battery but it is not recommended. The breakaway kit may not function properly in emergency situations because the trailer's main battery has other accessories powered from it which may drain some of its power. The auxiliary battery that comes with breakaway kits such as part # 20400 will be kept at a full charge from the trailer wiring 12 volt power because it has a built in battery charger. Most states require by...
    view full answer...
  • What Causes a Melted Circuit Board on Trailer Breakaway System
    I am sorry to hear about the issue you are having with your new snowmobile trailer. I cannot say for certain that I know exactly what issue caused the circuit board to melt but I suspect there was an issue with power jumping circuits most likely due to improper soldering connections on the board itself. In order to really narrow down what the cause of the issue is, it would be wise to take the trailer into a service center for diagnosis. However, the fact of the matter remains that...
    view full answer...
  • Breakaway Battery Continually Goes Dead
    The small breakaway battery shouldn't be going dead unless the breakaway switch is being pulled, there's a short in the system somewhere or the system has been incorrectly wired. The battery should be receiving a maintenance charge from the 12-volt power feed from the trailer connector on the tow vehicle. I would not recommend bypassing or altering the system at all. The breakaway system should have its own dedicated battery. I'll link you to an FAQ article that shows how the system...
    view full answer...
  • Is Hopkins Engager Breakaway Kit Compatible with Over 30 Tandem Axle Trailer with 12 Gauge Wire
    I reached out to my contact at Hopkins and she said that the Hopkins Engager Push-To-Test Trailer Breakaway Kit # 20400 has been tested on a variety of trailer lengths and so it will be good to use on your tandem axle trailers. The heavier gauge wire that is shown in the chart you sent in will just help to ensure that as much power as possible is traveling as far as possible.
    view full answer...
  • Is the Lid with Tester for Hopkins Engager Top Load Breakaway Kit Replaceable?
    The Hopkins Engager Push-To-Test Trailer Breakaway Kit with Built-In Battery Charger - Top Load # 20400 does not have a separate lid as a replacement part. The Breakaway switch is replaceable as is the battery, but to get that particular lid you need to replace the entire kit.
    view full answer...
  • What are the Dimensions of the Battery Box in Engager Trailer BreakAway Kit, # 20400
    I spoke with my contact at Hopkins to get the dimensions of the battery box in Engager Trailer BreakAway Kit, # 20400. The box measures 8 inches long by 4 inches wide by 6-1/4 inches tall overall. I have included a link to the installation details for this kit for you to view.
    view full answer...

Do you have a question about this Trailer Breakaway Kit?


Used Items Available

Condition: Like New

Notes: May have damaged packaging or minor cosmetic blemishes.

Our Price: $41.22
Secure Checkout


  • Why etrailer.com?

    At etrailer.com we guarantee:
  • Highest quality trailer breakaway kit for the best price.

    Our Lowest Price Pledge ensures you will never overpay for the parts you need.
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate trailer breakaway kit information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Expert Research:
Mike L
Expert Research:
Michael H
Expert Research:
Jameson C
Expert Research:
Adam R
Expert Research:
Victoria B
Updated by:
Adele M
Updated by:
Laura H
Updated by:
Sarah W
Updated by:
Alexander C
Updated by:
Brian T
Installed by:
Cole B

At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.