Forum Discussion

budwich's avatar
budwich
Explorer
Sep 12, 2015

Break away battery charging?

son-in-law has a equipment trailer (tandem wheels, ball hitched) that he uses for both work and recreation. It has electric brakes with a small battery in the junction box to provide power in the case of a "break away". There is no charge circuit hooked up to it so the battery has died (and likely is no good because it was not maintained). I was wondering what people do for these. On my TT, there is a normal battery with "proper" charging circuit both from the trailers converter when hooked to land ac and from the tow vehicle when hooked to the TV.

Is the "hooking to TV vehicle battery source" (pin xx?) the "normal" or do people just regularly take it to a battery charger when required?
I have checked the 7 pin connector and there is battery on the "black" wire (pin?)... not sure if his trailer uses it for anything right now... maybe for inside lighting. I didn't have time to check everything out as he was chasing wiring issues after replacing a "chewed plug" (darn dog)... :-)
Toy Haulers
  • Y-Guy's avatar
    Y-Guy
    Moderator
    Sep 12, 2015
    My previous trailers both RV & flatbed all were wired to charge while towing. However couple of our previous tow rigs were setup to charge but they did not come with the necessary circuit breaker to allow charging. Had to buy them separately to actually charge.
  • boogie_4wheel's avatar
    boogie_4wheel
    Explorer
    Sep 12, 2015
    Every flatbed and horse trailer I've owned, the break-away battery was charged by the truck/vehicle. All were 6 or 7 conductor plugs.
  • RoyB's avatar
    RoyB
    Explorer II
    Sep 12, 2015
    I think some of those small sealed batteries are just throw away type... My utility trailer had one maybe around 5Ah capacity but it was in a sealed box under the frame and the terminals not easily accessible... Its only needed to work for just a couple of minutes when stopping the run-away trailer...

    My neighbors flat bed trailer has the surge brakes on it and doesn't require a Brake Controller module... I have never noticed anything about where his battery was located or how big it is...

    Lots of good info on ETRAILER.COM site on Trailer Brake systems including the battery maintenance etc.... They suggest you not hookup a constant trickle charge as that will over charge the battery. They have a very inexpensive charger adapter unit that plugs into the 7-way trailer connector on the truck that is a smart trickle charger and will not over-charge the small battery. This would be using the 12VDC coming from the truck start battery setup. Also has a light warning system setup to tell you the status of the small battery...

    Roy Ken
  • Gonzo42's avatar
    Gonzo42
    Explorer
    Sep 12, 2015
    Brake Buddy has a charger module which contains diodes and a fuse. It gets wired to the cable connector from the towing vehicle.
  • Bedlam's avatar
    Bedlam
    Moderator
    Sep 12, 2015
    If the trailer sits for long periods without being connected to a tow vehicle, the battery may lose some charge. You can add a 5-10w solar panel to maintain the brake battery so it lasts longer. My enclosed trailer had the same setup but now has a large 5-battery bank in the PowerArmor box on the tongue.
  • budwich's avatar
    budwich
    Explorer
    Sep 12, 2015
    thanks for the info. I like the "kit replacement" as that will "control charge" the battery. The trailer does get used a lot for work so it will likely have 12v coming at the battery for large portions of time which would probably not be good so the kit would be a good idea.

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