I am in the middle of a DIY battery relocation, but i don’t have enough wire to have both the positive and the negative going back to the trunk. So i was wondering can you just do the positive and then have a short wire in the trunk that just grounds out into the floor? Or do you have to use the actual terminal from the engine bay?
Noooo.
Ground the battery to the chassis (perferably less than 2 feet of ground wire).
And ground the old negative battery terminal. to the chassis as well. Make sure you scrape paint away and the ground is good and solid.
You want grounds to be as short as possible. If they are to long (high resistance) it can make electronics do funny things
So basically, long positive wire doesnt matter but just make sure to ground out both negatives really good.
yes sorta, in reality the electorns travel negative to positive. So ure having short grounds is easier on electronics and doesnt mess things up like sensor and such. See if u can get a pic of a reloaction kit somewhere to give u an idea. And what guage cable are u using for ure postive and negative runs, too small will mess things up too.
both negatives…run the power form the fuse box to trunk as u did then ground the negative to a chassis sourse in the truck usually by the inner wheel well…
Make sure u either get a sealed battery like an optima, or get a battery case because most batts emit gasses that leagally need to be vented if the batter is located in the car.
But no one will ever check that 
Id get an optima eventually though.
Is it actually dangerous not to have the battery vented or is it just “legally” dangerous?
It is acutaly dangerous.
Some cars can catch fire if its not vented and the car is parked in the hot sun for a day or so.
were exactly in the trunk are you going to put it? are you doing this conversion to save space, or for weight or what? curious cus im going to do the same thing, im just not sure were im going to be putting it…
the best thing for weight distribution is behind the passenger back seat, but unfortunatly the gas tank is right there.
Best spot is passenger side close to the middle. But as long as you are in the general area your ok
As to the safety of your battery, you really want to be careful here. Def. get a sealed battery like the Optima’s, because batteries emit hydrogen gas when you charge them. Since a regular lead-acid emits the same funny gas as the Hindenburg liked, and cause you have a high amp, 12 volt battery, be very careful with it. It shouldn’t be a problem in the hatch or trunk, but keep in mind this is where the fuel tank is located! Never jar your battery too much or throw too much cargo back there over those terminals either! If you put it out back, even with a sealed battery, never risk any metal parts coming into contact with the terminals or shorting them out. There is really no safe place for the battery except where it can’t be touched. So just take careful precautions.
Yes, you want to ground the battery as close as possible to the battery itself. This is due to the fact that during shorts or other electrical faults, including normal operation of the battery, the electricity will take the least resistant path to ground. Usually, this also means electricity will take the shortest path to ground. So keep a giant big fat ground really close to the battery and make sure you drill a solid hole in your chassis and properly mount your ground where there is little chance for corrossion that will mess everything up.
Anyways, battery relocation has been done before in these cars and probably very safely. Don’t listen to me; just take a common sense approach.
:lol: