Where to go through firewall for battery relocation?

[brucepick]

Where to go through firewall for battery relocation?
'97 Civic HX Coupe with a/c (a/c components behind glove box).

I'm keeping a regular battery in the oem location (passenger side firewall) so probably can't go through behind the battery. Big deep cycle battery will go in trunk. See (Second/bigger battery to take a Load off the Alternator) to read all about why and what etc.

Pretty much open space available on driver's side, near brake booster. Drill there??

Someone said make hole on passenger side, below oem battery location but - -
I checked near the hose a/c drip drain hose, way below battery area. Looks like I'd have to drill way down near the big cross member, it doesn't look like a good place to work.

Any comments?

[oil pan 4]

Find something already going through the fire wall on the inside compartment, look under the hood to see if there is room and drill next to it.
That is what I do.

[instarx]

If its going to be in the trunk why run the cable through the passenger compartment? Route it underneath the car.

[Tesla]

x2 for under the car,
have a good look under the vehicle and under the bumper covers , in all the nooks and crannies, most vehicles have lots of unused holes throughout the body with rubber plugs just to seal them, you may find a suitable one.
Remember you only need to run one wire as the positive, as the negative can be earthed near battery location.
Use additional sleeving on the wire for extra protection as there will be a fair bit of current running through it.
Think about using a fuse at either end of the wire as well, because you may have power supply at both ends of the wire.
When you are ready to go, post up your circuit diagram to get feedback on things you may have missed, better to only do the job once, and ensure it is safe.

[mcrews]

WHen I moved the pattery to the trunk on my 66 mustang, I ran it under the body. Then drilled a hole and used a dounut gromet. And I only ran the positive cable as the tesla suggested.

Also if I remember, I ran a heavier cable......

[oil pan 4]

I wouldn't run it under the car, if it rubs through on the axle or something it could cause problems. I would rather run it throught the inside of the car under the carpet or hidden by the trim.
On a rear wheel drive set up can you can drill a hole throught the transmission hump near the fire wall and be right at the starter.

[mcrews]

You would attach it to the under carriage...... It would never be 'lose'.


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[brucepick]

Thread title:
Where to go through firewall for battery relocation?
'97 Civic HX Coupe with a/c (a/c components behind glove box).

It will go through the firewall, then under the interior plastic rocker panel cover towards the rear.

The question is, where to go through the firewall? Or maybe through an existing plastic plug in the inner fender wall into that cavity, then to the rocker panel area.