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Hopkins Engager Push-To-Test Trailer Breakaway Kit w/ Built-In Charger - Side Load - 7" Wire

Hopkins Engager Push-To-Test Trailer Breakaway Kit w/ Built-In Charger - Side Load - 7" Wire

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Hopkins Kit with Charger - 20099
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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 w/ Built-In Charger - Side Load - 7" Wire part number 20099 can be ordered online at or call 1-833-496-1390 for expert service.
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Hopkins Trailer Breakaway Kit

  • Kit with Charger
  • Side Load
  • Hopkins

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.


  • 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
  • Side-loading case is easy to access from the side
    • 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


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

20119 Hopkins Engager Break Away System with LED Battery Monitor and Charger - Side Load - 5 amp/hrs - 7" Wiring


Item # 20099

Installation Details 20099 Installation instructions

California residents: click here

Customer Reviews

Hopkins Engager Push-To-Test Trailer Breakaway Kit w/ Built-In Charger - Side Load - 7" Wire - 20099

Average Customer Rating:  4.8 out of 5 stars   (519 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.


The lid of the battery box was almost impossible to open due to little plastic latches that were very hard to depress to unlatch the lid. No instructions were included on that. When I got the battery box mounter (replacing a previously installed one) the lid flew off the first time on the road, despite my having pressed the latches home as firmly as possible. Don't bother!

I will have our Customer Service team reach out to you.
-- Etrailer Expert Jenny N - 04/15/2022


Installation was easy as this was a rep lacement.


While Hopkins has made a similar product for ages, this newer iteration is less easy to use. Instead of an actual button, to check battery level, you have to push the plastic casing in, with your finger. I can’t do it. So, you essentially need a tool to check battery level. Lame. I wish my older version still worked.


Helpful and courteous good source for trailer needs. Will be buying from again.


I will just make this short, overall it’s a good product, straight forward, easy to install. I wanted something that would keep my break away battery charged. With a built in battery charger and indicator this fit the bill. I however find that it is very susceptible to rain intrusion because there is no seal between the lid and battery box. The charge indicator light will come on and kill your battery, so because I needed this thing on the road, I dried it out and sealed it up with silicone. I did contact E-trailer and the where very helpful with my issue.


I had made several purchases from Etrailer and I have always got great parts service and fast shipping. We all work hard in life to be able to enjoy our hobbies. Rather it be Camping, hauling your race car to the track or keeping your work trailers in good working order. It is nice to have a company that is there to help you maintain your equipment in a economical, knowledgeable,and friendly way. If you are looking for advice,quality parts and trustworthy service look no further. Thanks Will and etrailer for helping me get me rig back on the road and safer. You guys are the best!


I buy all my trailer parts from here. Will not buy from anywhere else. Great product selection, prices and fast shipping.


Got my breakaway kit in 2 days. It took 2 Hrs to GREAT>>>>>it replaced the 7 year old dead batt and kit on trailer.
My trailer don't have a "power" wire for the charger..if your trailer does cut 30 min's off install time. As a professional truck driver
SAFETY FIRST on my trailer...and the Test button lets me know it is good to go.


I bought this brake away system one year ago and have had zero issues. I like the display and the test button still works. Great product, this trailer lives outside far so good.


Received order promptly,it was what I needed. To repair my trailer braking ability, my trailer is now safe to operate on the highways . Thanks.


The Hopkins battery box and break away switch showed up in record time with a fully charged battery. I also purchased a 7 blade plug / 24' 7 wire / 2 termination boxes. My old horse trailer has 18 various lights, some always hot, some on toggle, some running lights, stop and turn signals. I used 2 term boxes, front and rear, to help me in chasing future shorts but couldn't find a termination box at my local store. Etrailer had everything I needed to complete my project. I'm looking forward to purchasing trailer tires/rims from this company. The prices can't be beat, assuming free shipping.


Arrived as scheduled. I was replacing stock unit so I only had to drill one hole and cut and splice wires. Very simple and easy installation. Product seems tough built and so nice now to check battery with the push of a button.


Arrived within a couple of days, everything I thought it would be, took a hour to mount because I soldered and heat shrunk all connections. Everythng I've ever bought from etrailer has been quality parts.


so far so good, much better than the top test unit. over time the top test button would take water in and short out the board inside. this one having everything on the side works much better


purchased 2 roof vents and a breakaway kit with charger.Very good quality and very good and quick service.Hopkins breakaway kit has battery with charge control and switch with cable and a great price. Ventline basic roof vents with screen and hand crank and a great price too!!!

I have purchased these product previously and never had any problems with either. Thanks
Bader,dennis - 10/08/2018


Bought this to replace the box that was torn up by thieves who stole my trailer. Previous box did not have the battery charge tester, so this is a nice upgrade. Very durable construction. Easy installation and instructions, which included a good drawing. Super fast shipping, which prompted me to order more items. Have dealt with in the past, and I am glad that I returned.

Hi Patrick, thanks for the one year check-up.I have had no issues with the kit, it all works like it is supposed to. Thankfully, I havent had to test it for what it is designed for.
-- comment by: Gary - 02/14/2014


I converted my car trailer from surge to electric and it could not have been easier
The box was perfect for my needs and has held up well for the first year
All the parts from one site at a great price!

A year later and this product has held up and worked perfectly. Was easy to install and of good quality. I would buy this again if I had a trailer that needed one.
JAY M - 04/25/2020


Highly recommend. Own a 99 F250 7.3 diesel.

install. No issues. We have not had to use the break away aspect thankfully but have no worries that it would work well if the need ever arose.

We replaced our breakaway due to hitch failure on the truck. The bolts had loosened over time and one was missing. The whole hitch system fell to the ground under a full load at a red light. After my husband hyperventilated we were able to get traffic to stop and go 25 feet to safety.

We are very familiar with the need for a break away and highly recommend. What happened to us is rare and our mechanics are so paranoid now that inspection of hitch systems no matter the truck are fully inspected so far they have found and prevented five potential disasters.

All of our replacement items came from etrailer....hitch...ball..tongue and breakaway. We upgraded the weight limit of the hitch matching the weight to ball and tongue. We are currently saving to replace our jack to a more heavy duty easy use high weight bearing. When we do we will head to etrailer for our new jack.

Highly recommend this company and all of the associates we have talked to have been great.

Btw upgrading the hitch and tongue to handle weight has helped our hauling ability, ride and fuel. mileage.

Have a wonderful day


This is a very good product.We have it on a goose neck horse trailer.Would buy it again

Great Product would buy again
Peggy M - 04/25/2021


Well, you may not see the actual brake controller in these shots, but I wanted to display just how much etrailer product was used to restore this old trailer. Re-decked the trailer, new wheel bearings, added brakes on all 4 with this brake controller and battery powered emergency disconnect... new rust protection, primer and paint, new lights and wiring all the way around, new wiring harness/box, and new tire carrier. Nearly all product except the decking and paint was from etrailer. the customer support was fantastic, I highly recommend this company!


The product itself was fine. However, no instructions were included. It would be nice to have those for reference.

Nikki N - 06/23/2021


Item came with NO installation instructions. Had to search, download and printout on my own. Item P/N was NOT listed on mfr's site but did find instructions under a different PN. No mounting hardware (screws) were provided. Item was successfully installed on Utility/Car Mover trailer and appears to work properly. Battery capacity is minimal (5VA) - will power a single axle brake (5 amps) for less than an hour. Tow vehicle battery charger (12v) circuit is mandatory. No provision for an external battery charger connection is provided. DO NOT TEST while electrically connected to tow vehicle - it will damage your Brake Controller. This is important because connecting the breakaway switch lanyard as recommended requires pulling the plug from the switch which back feeds 12v to the tow vehicle's brake controller. Must connect the lanyard BEFORE connecting the trailer electrical cable and vice-versa when disconnecting. Switch mounting plate is very thin and flimsy - easily bent when applying force necessary to reinsert breakaway plug. Must hold the housing while inserting. Do not install the battery housing or switch where subject to possible external physical impact forces or loads. They are both plastic and easily damaged.


Item was a perfect replacement. Very similar to the original of the same brand, and even the mounting holes lined up perfectly. I've installed it on a 30 foot flatbed PT Trailer Gooseneck and it works great!

Product has been working flawlessly. Its been great!
Art - 06/18/2019


Good price, easy to use, no issues. Placed on drawbar for easy access.


Items were poorly packaged. Grease caps were damaged. Grease seals were sized wrong. No instructions for breakaway switch. Brakes were not assembled properly causing significant time troubleshooting the issue. Called customer service, representative sounded insincere when apologizing. E trailer did send new grease caps, did not offer any compensation for incorrect grease seals. They also told me to contact Hopkins regarding an issue with the breakaway switch wiring. Overall good pricing, poor packaging, and mediocre customer service. After all the positive reviews, I expected more.

Show More Reviews

See what our Experts say about this Hopkins Trailer Breakaway Kit

  • How to Install a Trailer Break Away System
    I do not recommend that you bypass the break away system because in many states it is a requirement to have a working break away system. Trailer brake magnets will have one power wire and one ground. The power output from a break away system will go to the magnet power wire. The input from the trailer connector goes to the breakaway switch. We do have a handy FAQ article and video that I have linked for you that will help. I have also linked an FAQ article on testing break away systems...
    view full answer...
  • Trailer Brakes Not Working When Using Hopkins Engager Trailer BreakAway Kit # 20099
    The Hopkins Engager Trailer Breakaway Kit, part # 20099, uses the 12V power wire on your vehicle 7-way connector to charge the breakaway battery so it can activate your trailer electric brakes in the event of a trailer disconnect. Your tow vehicle battery provides the charging voltage for the breakaway battery (but only when the engine is running). I suggest you review the linked article concerning the installation of breakaway kits. This covers important details for both installation...
    view full answer...
    Image 1 for
  • Testing Trailer Brake Magnets With Full 12V Power Supplied Using the Brake Controller Override
    In order to deliver full 12 volt power to your brakes while performing a pull test you can also use the override functions on your brake controller. This will avoid installing any switches, or disturbing any of the existing functional wiring. Switches can be forgotten, and additional connection points or unnecessary splices of the breakaway system can lead to problems like corrosion down the road. To use the override function on your brake controller you would turn the power of the brake...
    view full answer...
  • Will Brakes be Off with No Trailer Battery and Not Connected to Tow Vehicle Using Breakaway System
    If there is no power source (no battery, trailer not plugged in) then the brakes will be off in regards to using a trailer break away system like # 20099. I have included a couple of links that will help explain installation and testing of a break away system for you.
    view full answer...
  • Troubleshooting a Breakaway Kit Installation that Locks Up Trailer Brakes All the Time
    .27 volts would not be enough to lock your trailer brakes. I would recommend you check the voltage of the brake output circuit of your trailer wiring to determine what kind of voltage is there if anything. I would also check the wiring of your Engager Breakaway Kit # 20099. It sounds like the wiring is off somewhere. You might try uninstalling the # 20099 and seeing if the brakes stay locked up. Check out the picture I attached that shows how the breakaway kit should be wired. I also...
    view full answer...
    Image 1 for
  • Troubleshooting Engager BreakAway Kit # 20099 When Battery Is Overheating
    I spoke with my contact at Hopkins about the Engager Trailer BreakAway Kit, part # 20099 you are using on your Airstream. They told me that the battery being so hot is an indication that either the battery is bad, or there may be an issue with the circuitry on the breakaway unit. You will want to make sure the installation to your 12 volt power source has been completed as the instructions state. The white wire should be grounded to a clean bare metal surface on your trailer. The black...
    view full answer...
  • Does the Engager Trailer BreakAway Kit with Charger and Tester, # 20099 Come with Instructions
    Yes, the Engager Trailer BreakAway Kit with Charger and Tester, # 20099, does come with instructions, which I have linked for you. There is also a wiring color code on the box lid. If you look at the second picture on the product page you will see the color code information. The more detailed wiring instructions found in the manual for the kit are as follows: 1. Splice one blue wire of the Break-Away Switch to the electric brake wire coming from the trailer side connector. 2. Connect...
    view full answer...
  • How to Test the Hopkins Engager Trailer BreakAway Kit
    On the Hopkins Trailer Breakaway Kit, part # 20099, when you push the test button the green LED will light if the battery is over 12 volts. If the battery is less than 12 volts the red LED will light illuminate. I would also recommend to check the wiring of your breakaway kit. I am including a link to a video of the breakaway kit being installed. 1 - Connect one black wire from the breakaway switch to the blue electric brake wire coming from the trailer side connector. 2 - Connect other...
    view full answer...
  • Does the Hopkins Engager Trailer Breakaway Kit Have a 5 amp Battery
    Yes, I spoke with my contact at Hopkins and he informed me that this Engager Trailer BreakAway Kit # 20099 is on a 5 amp circuit and should work well for you. I attached installation instructions for this product for you to check out also.
    view full answer...
  • Trailer Brakes Come On Instead of Charging Battery in Engager Trailer BreakAway Kit 20099
    First, it is recommended that you charge the battery before installing the system. However, there may be another problem. It sounds like there could be a wiring issue or an improper ground that is causing a short and making the brakes engage. It seems that you may have the the wire that should go from the battery to the trailer connector going to the brakes instead. That would engage the trailer brakes on full and that would not charge the battery. Take a look at the wiring FAQ I have...
    view full answer...
  • The Battery on the Hopkins Engager Breakaway Kit is not Charging When Used With a 2007 GMC Sierra
    The Hopkins Engager Breakaway Kit, # 20099, takes about 20 minutes to recharge. Your 2007 GMC Sierra New Body must be running to charge the battery. The charging light on the breakaway kit will always stay on as long as the trailer is connected to the tow vehicle, but that does not mean the battery is charging. If you let your vehicle run and the battery will not charge, then you can take the battery to a local automotive store and have them test the battery. I have linked the installation...
    view full answer...
  • Do Your Breakaway Kits Meet DOT Requirements
    Yes all of our breakaway kits meet DOT requirements.
    view full answer...
  • Explanation of How Trailer Breakaway Kit Works
    The Hopkins Engager Trailer Break-Away Kit works by applying 12 volts of power to the trailer brakes when the plastic key is pulled out of the switch box allowing the circuit to be completed and power applied from the breakaway battery. If the trailer coupler should come off of the trailer ball, the safety cable pulls the key out and the connection is made to stop the trailer. The included rechargeable battery is charged by the auxiliary power wire from the tow vehicle which must be connected...
    view full answer...
  • Battery with the Engager Trailer BreakAway Kit with Charger and Tester # 20099
    For safety reasons you need to make sure the battery is fully charged before use. The battery will most likely have some charge from the factory but that charge can dissipate between the time it is manufactured until you receive it.
    view full answer...
  • How to Wire the Engager Breakaway Kit to Charge the Breakaway Battery
    The black wire on the Engager breakaway system # 20099 will be connected to a 12v auxiliary power wire coming off of the trailer connector. This wire is typically the number 4 black terminal in the 7-way connector, but you will need to test to determine if your plug is wired this way, as the auxiliary function can also be located on the center pin. Installing the black wire from the breakaway system to the 12 volt power source will allow the battery to charge when you have the trailer...
    view full answer...
  • Wiring a Trailer Breakaway Switch on a Trailer with an Existing Winch Battery
    Yes, a breakaway kit can be wired in one of two ways to the trailer brake system. The first way would be to use the Engager Trailer BreakAway Kit with Charger and Tester, item # 20099, and splice off of the power wire that maintains the winch battery on the trailer to charge the battery included in the kit (see instructions). This is the recommended method of installing a breakaway kit since many states require that a breakaway kit with separate power supply be used. The second option,...
    view full answer...
  • Where Do the Wires in the Brake Away Switch Connect on a Trailer
    You will splice one wire of the Break-Away Switch to the electric brake wire coming from the trailer side connector. The other wire on the switch connects to the break away box. It should not matter which wire is used for which function. I have included instructions for the Engager Trailer BreakAway Kit with Charger and Tester, # 20099, that will help you to wire the break away switch and the rest of a brake away kit. The referenced kit has a charger, if your break away system does not...
    view full answer...
  • The Engager Brake Away System, # 20099, Does Not Engage The Brakes When The Pin Is Pulled
    On the Hopkins Engager Trailer Breakaway Kit, # 20099, you should test the black wire on the battery box to make sure you have power going in to the battery box. The black wire will be connected to a 12v auxiliary power wire on the trailer connector. If you do not have power on the black wire you will want to make sure you have the white ground wire from the battery box connected to the ground wire on the trailer connector and that the black wire is connected to the 12v auxiliary wire...
    view full answer...
  • Measurements of Battery Box For Hopkins 20099 Trailer Break Away Kit
    The Battery Box for the Hopkins Engager trailer break away system measures 5-5/8 inches wide by 5-1/8 inches tall by 4-1/8 deep. If you click the provided links, you can see a trailer breakaway system FAQ article and an install video that you might find helpful.
    view full answer...
  • How Does the Engager Breakaway System # 20099 Install
    The black wire on the Engager breakaway system # 20099 will be connected to a 12v auxiliary power wire coming off of the trailer connector. This wire is typically the number 4 black terminal in the 7-way connector, but you will need to test to determine if your plug is wired this way, as the auxiliary function can also be located on the center pin. Installing the black wire from the breakaway system to the 12 volt power source will allow the battery to charge when you have the trailer...
    view full answer...
    Image 1 for
  • Trailer Breakaway System Recommendation for a 1993 Horse Trailer
    The most popular trailer breakaway kit we offer is the Hopkins Engager part # 20099. This comes with a charger and a battery, plus a display on the box to let you know exactly what condition the battery is in. I attached an install video for you to check out as well.
    view full answer...
  • Troubleshooting Brake Controller that Says It's Not Connected to Trailer
    This is a fairly common problem that is almost always due to corrosion on the trailer connectors. Check both the connector on the tow vehicle and on the trailer for corrosion and/or a bent pin and fix as needed. I attached a help article on troubleshooting brake controllers for you to check out as well.
    view full answer...
  • Do Trailer Break Away Batteries Need to Be Installed Right Side Up
    We offer break away systems from Hopkins and Tekonsha. Tekonsha uses glass mat batteries, while Hopkins uses gel filled batteries. Both types of batteries are sealed, and both manufacturers tell me that the batteries can be installed in any orientation you wish. For more information on trailer break away systems, click the provided link.
    view full answer...
  • Does Ground Wire Need To Be Attached To Trailer For Hopkins Engager Trailer Breakaway Kit
    I have attached a link to an installation video for the Engager Trailer BreakAway Kit with Charger and Tester, part # 20099. A weak or loose ground can give you all kinds of problems including the charger not working as you described. In the video, the white wire is attached to the junction box with a ring terminal. A wire then runs form the junction box and is attached to the trailer frame. If you do not have a junction box you can put a ring terminal on the white wire and attach it to...
    view full answer...

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