Battery relocation question

[Rittmeister]

I am planning on moving the battery in my S13 coupe to the trunk soon, using a Summit relocation kit and a few other goodies. I've got the routing for the cables figured out and so forth but I'm wondering how to secure the battery box to the trunk floor. Should I just use a couple fender washers and bolts, or what?

This is the kit I'm using: Summit SUM-G1231-K - Summit® Premium Battery Relocation Kits - summitracing.com

Anyone have experience with it? If so, does it include a means to secure the box?

Also - where in the trunk is best? I prefer to mount on the passenger side (if I'm going to do this at all I might as well get better weight distribution) towards the back, but that's right over the fuel tank; I don't want to go drilling into the trunk floor only to stick the drill into the gas tank underneath.

I wouldn't do this at all but I'm getting tired of my little Miata battery going flat in the winter... cold+less driving = tired battery

Any thoughts appreciated.

[ChiSleepyEyes]

keep the miata battery and get a battery tender for when u arent driving, get the waterproof version so it ca stay outside and it does all the work for you. Turns on when battery charge is low, turns off when charge is just right. i have been selling them for a little over a year for around 27$

[racepar1]

The trunk is not best. It is too high. If you feel you need your backseat and still want to move the battery just make sure to keep it within the wheelbase. If you mount the battery all the way at the back of the trunk it has a pendulum effect that you can actually feel if you are sensitive enough.

[Rittmeister]

Interesting thought on the tender. I assume this runs off 110v house current?

Is this really a unit I could plug in, connect to the battery, and ignore? I've read that the less expensive ones have to be watched; that they can damage the battery if not disconnected at the right time. ChiSleepyEyes - can you provide a link to the model you're selling?

I may consider this, but another reason I'm thinking about the relocation is to help alleviate issues like the headlights dimming when the rad fans come on and that sort of thing.

[sliEighty]

i have the relocation box for sale but it doesn not have the pos cable which you can get for pretty cheap at any auto store. i put mine right behind the back seat it fits nice there. but it comes with everything needed.

[ChiSleepyEyes]

Battery Tender Waterproof 800 12V 800mAh - Deltran Battery Charger DBT02200150DLWH - Batteries Plus
link as asked for^^
i work for batteries plus and have been for about a year and 3 months. and yes, you can hook these up and leave them, they are equipped with a auto float mode that allows them to shut themselves on and off when charge either drops or hits capacity.

[Rittmeister]

Thanks for the link.

Racepar1, it will go in the trunk if I do this at all. Despite seeing some track days and probably a trip or two to the drag strip this is still basically a street car, and the back seat will stay for now. Makes sense to mount it towards the front of the trunk though, based on what you've said.

I appreciate the opinions so far but no one has actually answered my question - what's the best way to mount the box to the trunk floor? And how can I go about drilling (if I have to) without puncturing the gas tank?

[5150Fab]

Put a peice of tape on the drill bit set at like 1/4 inch or so for a depth reference and just be careful. Its thin sheet metal so just drill till you see that you went through, you prob wont even need tape for a reference.

If you go right next to the strut towers you will be right over the rear subframe not the tank.

[Pho Man]

So if the battery is moved right behind the rear seats. What about ventalation? will that be ok?

P.S. if you do move the battery to the trunk you will feel a differnce when your doing autocross or road racing. Also the pervious owner of my 95 decided to mount the battery in the trunk on the passenger side with some wood blocks and long screws! Moron!

[racepar1]

Originally Posted by Pho Man

So if the battery is moved right behind the rear seats. What about ventalation? will that be ok?

If you are moving the battery inside the car you should either have a drycell battery (not an optima, they are gel cells and do emit gasses) or a sealed battery box with a vent hose going out of the car. The OP's battery relocation kit is sealed and has a vent hose, I just hope he installs the vent.

[aznpoopy]

Originally Posted by Rittmeister

Thanks for the link.

Racepar1, it will go in the trunk if I do this at all. Despite seeing some track days and probably a trip or two to the drag strip this is still basically a street car, and the back seat will stay for now. Makes sense to mount it towards the front of the trunk though, based on what you've said.

I appreciate the opinions so far but no one has actually answered my question - what's the best way to mount the box to the trunk floor? And how can I go about drilling (if I have to) without puncturing the gas tank?

the two threaded metal rods go through the battery box and the floor of the car.

the kit comes with 4 lined nuts that secure both rods to the floor on both exterior and interior of the car.

while the threaded rods are meant to hold the battery in place, the fact that they go through the battery box means the box ain't going anywhere either.

the real concern is securing the battery, which is actually like... heavy. unlike the box.
but if you want to secure the box more, drill more holes and add more nuts and bolts. make sure you use something to seal the holes. that's all there is to it.

fyi this kit involves a lot of diy. you need to drill out the box yourself for running cables and all that. additionally the kit is only sealed in the sense that it comes with little grommets you jam into the holes you drilled. the box lid is sealed in the sense that the kit comes with a little strip of rubber or teflon that you peel off a roll and stick to the perimeter of the inside cover. make sure you add a fuse or circuit breaker for the positive cable.

[Pho Man]

Originally Posted by racepar1

If you are moving the battery inside the car you should either have a drycell battery (not an optima, they are gel cells and do emit gasses) or a sealed battery box with a vent hose going out of the car. The OP's battery relocation kit is sealed and has a vent hose, I just hope he installs the vent.

Ok I was thinking along the lines of some tubing going to the outside of the car wasn't sure though.


Anybody have pics of there setups?

[Om1kron]

Originally Posted by Pho Man

Ok I was thinking along the lines of some tubing going to the outside of the car wasn't sure though.


Anybody have pics of there setups?

I posted a battery relocation thread in the tech forums, a few people posted their set ups in there. Feel free to post pictures, and pendulum... big word!

[Rittmeister]

Originally Posted by aznpoopy

the two threaded metal rods go through the battery box and the floor of the car.

the kit comes with 4 lined nuts that secure both rods to the floor on both exterior and interior of the car.

while the threaded rods are meant to hold the battery in place, the fact that they go through the battery box means the box ain't going anywhere either.

the real concern is securing the battery, which is actually like... heavy. unlike the box.
but if you want to secure the box more, drill more holes and add more nuts and bolts. make sure you use something to seal the holes. that's all there is to it.

fyi this kit involves a lot of diy. you need to drill out the box yourself for running cables and all that. additionally the kit is only sealed in the sense that it comes with little grommets you jam into the holes you drilled. the box lid is sealed in the sense that the kit comes with a little strip of rubber or teflon that you peel off a roll and stick to the perimeter of the inside cover. make sure you add a fuse or circuit breaker for the positive cable.

Ah, finally, some info.

What do you mean by "lined nuts"?

And yes, I'm aware of the "some assembly required" nature of the kit. Need the vent tube, holes for the cables, etc, no problem.

I'm now undecided though, after doing more research on the battery tender idea. I don't really want to relocate, and was only truly considering it because I have an Optima I'm not using for anything else right now. The car is perfectly fine when it's warm, it's only during the winter months that it's a problem; small battery + not driven as much + cold weather = flat battery.

[aznpoopy]

the vent tube comes with it, along with a grommet for the tube.

the nuts for the threaded rod are "lined" in that they have an interior cavity lined with some kind of rubber or teflon or something

[xs240]

Originally Posted by racepar1

The trunk is not best. It is too high. If you feel you need your backseat and still want to move the battery just make sure to keep it within the wheelbase. If you mount the battery all the way at the back of the trunk it has a pendulum effect that you can actually feel if you are sensitive enough.

so best place is behind passenger seat?