Battery Relocation

[TurboWagon]

After looking at the recent R&T article on the SRT-4 and Speed3, for some reason after they said the SRT-4 had a better weight distribution, I wanted the Mazda to beat it in that category as well. (cabpatch)

Anyways, my friend used to have a '90 240SX and relocated his battery to his hatch area, this also helped his weight distribution but mainly because his car was already stripped of most of the interior upholstery, tar and belts, making him much lighter than an MS3 to begin with.

My question...Has anyone relocated the battery in the MS3 yet and if so, have you found the characteristics of the car to change? Thanks!

 

[autoxes]

It will help, but I don't think the change would be noticeable if not in conjunction with other weigh shifting / reducing mods like lighter parts in the front end.

 

[Falconx84]

this is the first I've heard of moving the battery for weight distribution.

Normally it's for more room in the engine bay. I probably wouldn't recommend moving it to the back in a hatch. Batteries release a certain amount of poisionous (and flammable?) gas. Not bad in a race car, not so good in a daily driver

 

[Mocoso]

this is the first I've heard of moving the battery for weight distribution.

Normally it's for more room in the engine bay. I probably wouldn't recommend moving it to the back in a hatch. Batteries release a certain amount of poisionous (and flammable?) gas. Not bad in a race car, not so good in a daily driver

BMW did this on the 2001-2005?(cant remember when the E46 ended) for weight distribution on the 330i... big hole in engine bay where battery should go.. and it was in trunk and had a vent hose from battery vent hole to the exterior of the car for the reasons you described

Havent heard anyone do it yet and while it would help with weight distribution Im not sure if it would significantly affect handling to warrant all the thick wires you would need to run from engine bay... changing out the heavy hood would prob be a better alternative but I still havent figured out why our hood is so heavy... is it safety, cost, or functional issue that required it to be so damn hefty?

 

[enganear]

I moved my battery front to back on a heavily modded auto-X Mustang and immediately noticed a big improvement in turn-in. An added benefit was battery life which exceeded 6 years because of reduced exposure to heat.

I will not do this on my MS3 because I do not want to give up the utility value of the hatch area and sticking a permanent battery box back there severely limits the size and shape of any cargo. I will, when the time comes, use a smaller lighter battery in the original location. Probably a Hawker AGM type.
-enganear

 

[amascio]

I'd rather have a lighter weight hood! That thing is HEAVY. My '08 Miatas' hood is light as a feather. Why didn't Mazda do the same thing on the Speeds?

 

[Vengure]

In my opinion for warranty reasons I would not do this however if you were determined I would suggest a AGM sealed battery no need to worry about venting gases released by the battery.

 

[enganear]

Another thing I do not like about rear mounting a battery is running unfused wiring the length of the car. Even if you do protect the wire with a fuse large enough to handle the starter load, you could start a helluva fire and never blow the fuse.

A friend auto-xes a Rabbit in SP with a 11 Ah AGM battery that weighs about 8 pounds. The MS3 would probably need twice that capacity to be streetable.

-enganear

BTW, AGM = Absorbed Glass Mat