Charging dump trailer battery through truck?

[Garrett2006]

I’m looking to charge my dump trailer battery from truck with the 7way pin & by installing a high amp kit that comes directly from trucks battery.

questions-
Will I be able to leave it hooked up while time trailer is connected during the day?

what keeps it from back feeding if dump trailer battery is low and feeding off truck battery when truck is shut off, but all still connected?

Is there anything I need to add to the kit I have the picture attached of to achieve this?

this kit actually could be used with dump trailer pump even without a battery from my understanding, but I’m wanting to use it as a back up and to charge the dump trailer battery; not do away with it.

thanks

 

[cqaigy2]

The setups i've seen are similar to that used for RV, where your vehicle charges both the vehicle battery and the RV battery. I haven't looked at one for awhile, but i think they are probably an arrangement of heavy duty diodes that allow current in only one direction, from your generator/alternator, to the battery. That way, the other battery can't pull power from on that has higher charge.

 

[ning]

You're looking for a "battery isolator"

 

[grsthegreat]

My dump trailer has a device hooked onto battery from BigTex trailer. It allows battery to charge when hooked up to truck. No external charger used all year long. I only remove battery for winter storage. I hook it up to trickle charger a few times during winter.

 

[Garrett2006]

My dump trailer has a device hooked onto battery from BigTex trailer. It allows battery to charge when hooked up to truck. No external charger used all year long. I only remove battery for winter storage. I hook it up to trickle charger a few times during winter.

Correct mine as well, but if it ever get to low it will blow the trucks fuse and then the truck will not be charging it anymore.

 

[nikerret]

See my thread, here:

2 AWG to rear of truck for power. - Ford Truck Enthusiasts Forums

All Things Towing - 2 AWG to rear of truck for power. - The issue I was having is my dump trailer battery was only good for four or five heavy lifts, per full charge. The trailer is only a year and a half old, but I've moved thousands of tons with it. Since I am not great about charging the...

www.ford-trucks.com

 

[RustyA]

Typically the 12v charge circuit at 7 pin is only hot with key on or engine running to prevent parasitic drain of tow vehicle battery from factory. If wiring of tow vehicle is modified it may disable this feature. If tow vehicle is newer the BCM might start throwing fault codes.

 

[grsthegreat]

Correct mine as well, but if it ever get to low it will blow the trucks fuse and then the truck will not be charging it anymore.

No idea. I do know Ive had the trailer 4 years without any issues.

 

[Renze]

When i worked in trailers and bodybuilding, i remember we put a separation relay between truck and trailer; when the truck alternator isnt charging, the relay disconnects the battery of the trailer from the battery of the truck: when using a vehicle winch or a rear tailgate lift, the trailer got its own battery.

We also installed an Andersen connector, used between electric forklift and its battery pack, with a quarter inch cable from the battery, to prevent wiring loom fire..

 

[JohnDeereJoey]

Your proposed heavy gauge wiring is a huge step in the correct direction...greatly reducing the voltage drop of the smaller wires in the 7-pin.

You can simply disconnect the wiring between the tow vehicle and trailer or rig up a relay that only connection the charge line when the truck is running. It is very possible the 7-pin charge line already does this, so that would make for a convenient way to control the relay.

If you want what might be the ultimate set-up, look into a dc-dc charger. Many are marketed specifically for charging trailer batteries from tow vehicles.