Adding a battery -- properly

[Lit'l Shinee]

When I got my teardrop it only had a straight wired mess hooked directly to the battery, which was located in the rear hatch. There were no
fuses, no ground blocks, no nothing. All of the running and tail light wiring was all tied together in a way that if something went wrong, you would have to cut it all out to fix anything. All of this rat's nest was located in the sleeping cabin, either under the mattress or at your feet through a hole in the wall that gave access to the battery. There was no color coding of the wire, the PO obviously used whatever scrap he could find so the wiring looked like a large box of crayons.

After tracing it out and figuring out what went to what, I have started rewiring the 12 volt stuff from scratch. I am trying to finish one part of the 12 volt at a time so thus far I have concentrated on the things that work off the connector that goes to the tow vehicle.

To date, I have installed a 7 pin connector, converting it from the flat 4 by using a junction box. I left the standard flat 4 wiring that was hooked to the lights in place. Most everything else has been replaced. Cleaned up a lot of the confusion by putting all the ground wires on a block fed by the main ground from the J box. (Have 2 frame grounds) Also tied in all the power/hot wires to a studded junction bar. Did the op check on this last night and everything worked as it should.

Now, I need to do the other side of the system, the interior lighting and 12 volt outlets and accesories. In other words, all the things that work off the battery. I have a fuse panel ready to install to run all these things but before I make the final plans, I want to be sure that I have the correct info for hooking up the battery to feed power to the fuse panel.

The battery is now located on the tongue, so the fuse panel will be about 10' away in terms of the length of wire that will be needed. From my reading here on the forum, looks like I need a 30 amp fuse very close to the battery and that 10 AWG wire should be plenty big enough for the 2 lights inside and 1 at the hatch. Amp draws are low, plus going to change everything to LED later on.

The question concerns exactly how I make that final connection from the battery to the fuse panel. Please pick the following apart and lend suggestions as needed. Remember, this is a new venture. I can follow simple instructions well so keeping it simple is great !!

1. ** I run the wire from the pos. terminal thru the inline fuse and directly to the interior fuse panel.

2. ** What about the ground?
Do I need another ground block inside and run a main ground to the frame? Or does it run to the negative terminal of the battery. Read about both versions of this. Confused a little ????

Sorry about the long winded post but wanted to give the full picture of the job.

Thanks much for any help with the final hookup,

Shinee

[madjack]

!) YES
2) run another 10ga wire to a ground bar, which I would locate next to the fuse block...no ground to trailer for this...some 12vdc fuse blocks have a ground bar built in...........
...all this is independent of the vehicle wiring.......................
madjack

[wlooper89]

I agree with madjack. Although the trailer running light ground is connected to the trailer frame, it may be best to have a separate ground wire connected to the interior fuse panel for the interior lights, etc. Since the distance to your fuse panel is the length of the trailer you have a good idea to put a master fuse near the trailer battery positive terminal. A 30A inline fuse would be good.
Bill

[Lit'l Shinee]

Thanks for the replies. Now to finish it all. FYI: None of the grounds on the trailer running lights are tied in with the interior stuff. I kept all of it seperate.

If I'm reading your answers correctly, I need to run the ground from the battery negative terminal.

Thanks again,

Shinee

[Miriam C.]

Thanks for the replies. Now to finish it all. FYI: None of the grounds on the trailer running lights are tied in with the interior stuff. I kept all of it seperate.

If I'm reading your answers correctly, I need to run the ground from the battery negative terminal.

Thanks again,

Shinee

I think you got it.

[planovet]

I agree with MJ and the others. I did add a cut-off switch in the line from the positive terminal to the fuse box. That way while stored or traveling I know there is no drain on the battery. Just a thought.

[Lit'l Shinee]

Thanks to all for the information. Think it will be an easy finish now. Want to get this thing out of the yard and in a campground asap.

Planovet -- Good point about adding a cut off swith. I will probably do that.

Shinee

[green_eyed_diablito]

just to make sure i understand:

do i have to ground the battery? or can i just run the neg wires from my lights straight to the battery? i will have a fuse block and a main fuse between the fuse block and the battery.

thanks,
miguel

[wlooper89]

Miguel,

The trailer frame is often used as ground for trailer running lights, similar to the way the chassis is used for DC negative in the tow vehicle. But if you have a separate ground wire from the trailer battery negative to the DC fuse panel in the trailer it is not necessary to also connect 12V negative from the trailer battery to the trailer frame.

There is an exception that will cause a connection between the trailer battery negative and the trailer frame. If one sets up the trailer connection from the tow vehicle to charge the trailer battery while towing, then the trailer battery negative will connect to the tow vehicle negative, which in turn is connected to the trailer frame for running lights in most cases. I have used this setup for some time and it does not cause a problem. A sticky about charging the trailer battery from the tow vehicle describes this if you decide you want to recharge the trailer battery while towing.

A converter can be added if desired to charge the trailer battery while camping if there is AC hookup. Some folks add AC outlets in the trailer for use when there is campground power. An extension cord and power strip can be used instead if you want to plug in AC items and keep it simple. One can obtain a power strip with built-in GFCI if desired for added safety. There are quite a few different options. Things can be relatively simple or fancier if you wish.

Bill

[Lit'l Shinee]

just to make sure i understand:

do i have to ground the battery? or can i just run the neg wires from my lights straight to the battery? i will have a fuse block and a main fuse between the fuse block and the battery.

thanks,
miguel

Today I finished the lighting and accesory wiring. I ended up using a fuse panel that had ground hookups on it also. No need for another ground block. In effect, this is the same thing as what Miguel says above about running the neg wires from the lights straight to the battery. All my grounds are on the panel with a main wire coming straight from the battery negative terminal.

I ran a 10 awg wire, with 30 amp inline fuse, from the positive post of the battery to the fuse panel and the same size wire from the negative post of the battery to the ground portion of the fuse panel. No ground from the negative battery terminal to the frame.

So far, all is working well. It took a good bit of work, tearing out and redoing and spent a few bucks for good supplies, but it's done. All labeled for easy identification. Right side work labeled with green tape, left with red. Also wrote up a listing of what's on each circuit. All wires removed from interior that used to run under the mattress. Put them under the trailer in flexible conduit running the length of the trailer.

Thanks for all the help guys,

Shinee