Charging Trailer Brake Battery

   #1  

covefarm

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Joined
May 16, 2011
Messages
27
Tractor
JD 7400, 5410, Kubota B8200
I have a 5 ton GVW flat bed trailer with dual axles and electric brakes. I rarely use the trailer. The brake battery does not get charged as a result. I thought it charges whenever the trailer electric is plugged into my truck and the truck is running but now I'm not sure it does charge. It's a 12 volt battery approximately 6" tall by 4" wide with flat blade terminals. Should it charge when my truck is running? Can I use a regular 12 volt battery charger to charge it? Appreciate the advice.
 
   #2  

Dmacleo

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Sep 11, 2020
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Location
Etna, Maine
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2010 MF GC2400
is the 12v constant on the tow vehicle actually hooked up and working?
easy to blow a fuse (eg the 2011 silverado 2500hd uses a 40A j case fuse) and if so battery won't charge.running dump trailer with bad battery can pop this fuse a lot....ask me how I know LOL
hard to say w/o knowing vehicle/pin specifics.
 
   #3  

slckeys

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May 10, 2018
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154
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ck4010sehc
Those batteries aren't exactly known for lasting long as well.

But first I would check to see if there is voltage going to the battery with your truck hooked up and running. Fuse is a simple place to start as mentioned. If not getting voltage, start working backwards towards your tow vehicle to see where it stops.
 
   #4  

Roadworthy

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Aug 24, 2019
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Southeast Washington
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Kubota L2501 HST,
Generally these are a small motorcycle or lawn tractor type battery. Three years would probably be considered a good life span. I do not recommend a regular charger. It can source too much current and boil the battery dry.
 
   #5  

Doughknob

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Oct 26, 2013
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ohio
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Deere X500, Bobcat CT4045
I have charged those small types on the 2amp trickle setting on my charger. An auto-shutoff charger is also a good thing.
 
   #6  

oldballs

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Dec 29, 2009
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Kansas...USA
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Kubota B2620 , Case 448 , Kubota B2650
I remove the battery from my now seldom used trailer....and....put it on the Maintainer now and then as it (battery) sits in the garage.

Cheers,
Mike
 
   #8  

MillWeld

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Feb 17, 2011
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410
Location
Durham NC
Tractor
Ford 641
It is my understanding that the little trailer battery operates the brakes if the trailer breaks loose from the truck severing the electrical connection between the truck battery and trailer brakes. As long as the trailer is properly connected what else does the trailer battery do? Is there a way to test if it can deliver enough current to operate the brakes without jacking up the wheels and unplugging the trailer brake connection from the truck and trying to spin the wheels? My trailer/brake system is about 10 years old so (based on this thread) I bet my trailer battery is toast. With the trailer disconnected I will measure the voltage and put a trickle charger on it if necessary. Need yout comments.
 
   #9  

deezler

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Jan 30, 2012
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Southeast MI
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Cub Cadet 7305, Kioti CK3510seh TLB
^ Yeah that is my assumption too. I think it should be lightly "charging" whenever plugged into the tow vehicle, no? It's a small battery after all. Since you only need it to work for 30 seconds in case of a towing catastrophe, does even a mostly dead battery provide adequate performance?
 

bdhsfz6

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Apr 11, 2015
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Northeastern Pennsylvania
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Kubota MX5800 HST & L6060 HSTC Formerly L6060 HST B7100 HST, L2550, L3010 HST, L3430 HST
I also have a trailer that is infrequently used. After replacing that 12V battery 3 times, I bought one of these battery adapters:

61TEbQYffvL._AC_SL1500_.jpg


I just plug in one of my 18V Dewalt power tool batteries whenever I use the trailer. The higher voltage doesn't seem to affect the braking and I've never had one fully discharge even on a long trip.
 
 
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