Charging a dump trailer battery

   / Charging a dump trailer battery #1  

bja105

Bronze Member
Joined
Oct 5, 2012
Messages
50
Location
Western PA
Tractor
Cub Cadet 147, Ford 80, 4610
I rented a dump trailer for a day, and made 10 short haul trips with it. On the tenth trip, the battery died, and I had to put it on the battery charger, then shovel some out.

I want to buy a dump trailer, and make sure my 2005 Durango will charge the trailer battery. I just checked, I have 12+ volts on the car's 7 pin plug at the pins marked + and -. That should do it, right?

I had guessed that I blew a fuse with all the short hops and charging, but I didn't find a blown fuse.
 
   / Charging a dump trailer battery #2  
I can't address the pinout, other than to say - yes, the 7pin is used to charge the battery. Mine does.
 
   / Charging a dump trailer battery #3  
Those pins charge but at a low rate, about 20 amps. While in theory it will do the job I suspect either all the short hops did it in or the trailer is not properly wired.

Chris
 
   / Charging a dump trailer battery #4  
My understanding is the bulk of the charge is in the first few minutes and ohms law would say most of the charging juice goes to your truck battery.
 
   / Charging a dump trailer battery #5  
On short hauls the vehicle charging system can't keep up generally, and if the battery is totally drained and you leave it connected to your vehicle it can drain that battery too.
I made up a 25' set of jumper cables from welding cable. Not only can you dump when the trailer battery is down, but you can take a 15 minute break and get a real good head start on charging it back up.
 
   / Charging a dump trailer battery #6  
That charging pin on the connector is probably only wired to work when the ignition is turned on.

It's probably not a heavy enough charge rate to keep it charged during short trips. Besides, if you look at the wiring, that may be only good for 10 or 15 amps max.
 
   / Charging a dump trailer battery #7  
I replaced the 7 pin charge wire fuse with a circuit breaker in my truck. That charge lead feeds the batteries on each of my trailers when hooked up to the truck. On one trailer I have the hydraulic tilt and a winch. The hyd. don't draw a lot but the winch does and would often blow the charge wire fuse. I also added 1.5A solar chargers to each trailer to keep the batteries topped off when not in use.
 
   / Charging a dump trailer battery #8  
Also helps to ensure someone didn't swap out the original battery for a plain car battery. Generally they come with a deep cycle battery which tends to do better under long periods of high load.
 
   / Charging a dump trailer battery #9  
If you buy a trailer I wouldn't depend on the vehicle as the sole source of charging the trailer battery. I keep the built in charger on my dump trailer plugged in at all times when not in use.
In winter I bring the batter inside and keep a maintainer on it.
 
   / Charging a dump trailer battery #10  
Bought my dump trailer from a rental place used, it will go about a month between charges (use it once a week or so), then I plug it in and forget about it, it has a NAPA maintainer installed.
 
 
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