Important
- Thread starter bshaw
- Start date
shortxjdoug
NAXJA Forum User
- Location
- Chattanooga tn
- Location
- Warsaw, IN
Got a question for the electrical guru's. I'm wanting to put a 12 volt battery on the front of our pop up camper and would like to be able to charge the battery while it's being towed down the road. I already picked up one of the 7 pin connectors to put on it. Do I just need to run a wire from the 12 volt pin on the connector and hook it to the battery? Do I need a breaker or fuse in between them?
- Location
- 29°58'28.9"N 99°15'15.5"W
Just run the wire. There is a fuse under the hood. Then put one close to the + of the battery.
- Location
- Warsaw, IN
I thought that was all I needed to do. Just wanted to make sure. Thanks
- Location
- Warsaw, IN
- Location
- 29°58'28.9"N 99°15'15.5"W
Depends on the wire size you run, if you are just charging a battery, then a 14g wire and 15 amp fuse is fine. if you want to run a 500 w inverter, then you might want to step up to at least a 6g wire and a 80 amp fuse.
Read this
<Edit> You will need to see what size fuse is under the hood. do not go bigger than that one, it is sized for the wiring on the vehicle.
If something should happen to the wiring in the trailer there is a possibility it could damage, or burn, the wiring in the vehicle.
- Location
- Warsaw, IN
Awesome thanks.
RedHeep
NAXJA #1499
- Location
- Landenberg, PA
I always step up the wire for a little piece of mind. Just as long as you fuse it correctly.
- Location
- Warsaw, IN
I will look at home to see what size fuse is on the xj and zj and make sure I don't go bigger than it. Wouldn't think it would hurry to step up to like 10 or 12 gauge wire. Just to be on safe side
- Location
- Columbus, In
It's a 5.9 Ben, it's an 87!
turns out the case I had lined up was bad anyways. It was a 99.
Smash Hole
GFY
- Location
- Smash HQ
Buy my front axle
it will work more betterer if you run some 10ga.
voltage drop over 14ga at that distance will make it suck for charging battery.
math says
14ga @ 15 feet with 15A of current goes from 13.8v to 12.6
10Ga wire at that same distance/current keeps it at 13.4
- Location
- Coshocton, OH
AFAIK There is no constant power for trailer fusing on an XJ or ZJ only a dead signal wire for a brake controller from under the dash to the rear. You will need to run a wire from the front to the back to get constant power/charging. If it where mine I'd run no smaller than 10AWG, and fuse on both ends with probably a 30A fuse. Buy good water/weather proof fuse holders, or they'll corrode up and be a constant headache after a few years.
- Location
- Warsaw, IN
Re: Re: Important
Well the zj already has the 7 pin plug in on the back. I'm changing the plug on the camper from a 4 pin to a 7 pin. Would I be better off going right off the battery or right from the plug with the 10ga wire and an inline fuse?
- Location
- 29°58'28.9"N 99°15'15.5"W
seanR approved
- Location
- Southern Indiana
- Location
- NE Indiana
That's what my buddy that ran a trailer hitch shop for years does.
mac 'have used the circuit breakers alot without issue' gyvr
RedHeep
NAXJA #1499
- Location
- Landenberg, PA
There's a good chance that either the 12v constant wire isn't hooked up to the battery or that it's woefully too small to charge the battery that you want to use. Remember that the 12v constant in a 7 pin plug is designed to keep the emergency breakaway battery charged on a trailer, which is very much smaller than the one you want to power 12v stuff in your camper.
A direct battery connection through the proper fuses with the proper size wire will ensure that you're charging at a rate high enough to charge that bigger battery. You can still run it through the plug for convenience.
