Is It Possible to Add an External Battery to Power Electronic Reverse Lockout?
Updated 08/12/2026 | Published 08/06/2026
Question:
Is it possible to install and mount an external battery to my trailer to power reverse lockout solenoid? I am needing to back up trailer manually and mine does not have a manual lockout pin so surge brakes keep locking up
asked by: Vince
Expert Reply:
Hey Vince,
Yes, you can add an external battery to the surge brake actuator on your trailer to power the electric lockout, but this isn't the preferred path to take. Typically, the electronic lockout is powered through a 5-way or 7-way connector, which provides the 12V power to the lockout from the vehicle's battery. With an external battery on the trailer, you can wire the battery directly to the solenoid, ground it to bare metal to energize it, and then the lockout will block the hydraulic pressure to the brakes when activated.
You do need to make sure your actuator is electric lockout-compatible. What kind of surge brake actuator do you currently have installed on your trailer? If you send me the brand/model of your actuator (or a photo of it), I can tell you whether a lockout solenoid can be added and how I’d wire the battery/switch setup.
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Deka Jacketed 2 Wire, 10 Gauge, Brake Wire - per Foot
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Vince
8/11/2026
Well, I have a DEMCO DA70. I have a 12v breakaway battery and box, as well as a switch so I want to wire it so I can just hit the switch and bypass the surge brakes. I get it's not preferred but I need to be able to hand back it up into a super tight spot with a tug that doesn't have a 7pin connector. I'm not doing it often as the trailer is empty since boat is at marina so need to do it very infrequently but good to have for when it's needed. I'm Just not entirely sure how to wire it all together. I don't think this model actuator has a manual lockout key slot.