Projects & Mods - Dynabatt Battery

:. Projects/Mods .:. Dynabatt Battery .:

Tools	Get From:
·Drill and drill bits	any hardware store
Materials:
·Steel Bar Stock	~$5 - Home Improvement - etc.
·Dynabatt Battery	~$150 - Performance Distributors (etc)

Update 2002/12/15
I found a new URL with a good place to get this battery for a lot less than what PD lists them for. There is a *ton* of battery information Here, and in this article, they list this as the same battery, along with several others. Check it out.

I just finished my first autocross with this new battery/bracket, and it didn't move an inch, and tech had no problem with it at all. Still hasn't had any issue starting my car, even after multiple sub-freezing nights. A+!

Introduction

The stock liquid lead/acid battery in a DSM weighs about 45 pounds. Up high near the front of the car, it does everything wrong - it's big, it raises the COG, increases polar moment, and just weighs. Replacing the battery with a smaller and lighter one is an good way to lose about 30lbs off the nose of your car. And, as it turns out, with this Dynabatt, it's also an easy and fast way.

Most folks will relocate their battery to the rear for improved weight distribution, but I didn't think that 13lbs was worth the time, cost, and effort. Plus, I didn't want to deal with all the rules involving relocated batteries, battery boxes, cutoff switches, and all that nonsense. So, I bought a Dynabatt, and installed it in my car where the Charcoal canister used to live.

Installation Notes
This installation took me about five hours, including time for pictures, buying new battery terminals, and the like. The only things you'll be sure to need are a drill and bits for making your brackets, and some steel bar stock. I used some 2x1/8" that I had lying around from other projects. It seems to be plenty stiff, and I was able to bend it using a hammer and the edge of my concrete steps.

First thing to do is get all the trash associated with the stock battery out of the way. Depending on how much stuff you've stripped out of your car, this will include:

battery tie-down (keep this!)
battery
-, +, and ground terminals
plastic battery tray
metal battery 'shelf' (4 bolts)
charcoal canister

Nothing is too tricky about getting the battery parts out. Four bolts hold the metal tray in place, and the wiring harness is zip-tied to it in a few spots. After that is out of the way, the next enemy is the charcoal canister. If you look around the driver's side of the canister, there is a clamp which you can undo. After the clamp is undone, there is a small clasp that will allow you to completely unhook the band clamp holding the canister in place. Remove. Last is a small plastic bit sitting on the subframe, held on by two Phillips screwdrivers. Remove this too. With this gone, there is a nice flat surface for your battery to sit on.

By a happy coincidence, the Dynabatt is almost the exact length as the width of the stock battery. Because of this, I used the stock tie-down to help in making a bracket for the battery. There are plenty of threaded holes down here from the removed battery bracket and charcoal canister, so it's just a matter of using them to make a bracket work.

I found a long bolt in my pile o' bolts and ran it through the "small" end of the tie-down and threaded it into the hole formerly occupied by the front support bracket of the battery tray. The tie-down is just a bit too short, so I used a bit of wood and a hammer to angle them out just a bit.

For the other side of the bracket, I used one of the holes formerly used by the charcoal canister's clamp. Since it is on the firewall, it is at roughly a 120* angle from the tie-down, so I needed to make a metal bracket to 'turn the corner'. I used a bit of bar stock and my trusty hammer to bend it into shape, and drilled two holes. For the bolt going from the tie-down to the bracket, I used the stock big-washered bolt with a nut on the other side. For the bracket to firewall bolt, I just used the one that had previously been there with the charcoal canister (fig 7)

You can see how well this ultimately fit (fig 8). After the battery was fitted, I bought new terminals, since mine were horribly bent and cracked. As well, the Dynabatt's posts are slightly larger than the OE ones. The new terminals were still a bit tight, but a gentle tap with a rubber mallet got them seated just fine.

Notice in the later pictures that I flipped the battery around. Due to tight clearances of the positive post and terminal to the frame rail, I turned it around to avoid the battery grounding out. As such, I had to pull the positive wires over to the firewall side, and move the negative wires over towards the front of the car. Nothing difficult there. (fig 9) You can see that I ended up inverting the wires with the fusebox, just for the sake of routing.

Be sure to have your ground strap bolted down somewhere, and make sure that the negatives and positives won't try to worry themselves loose and hit eachother, and you should be good to go. This battery is held down very tightly with this setup, so I shouldn't have any difficulties passing tech at the strip, autocross, or the track.

Impressions
Not a lot can be said here. The Dynabatt weighs in at only 13.5 lbs, versus the stocker at 45 or so. That's a lot of weight to have off the front end. Even better, the battery is now quite low in the chassis, improving the weight distribution further. The extra room in the engine compartment is wonderful - I won't have to pull the battery when cleaning the K&N filter anymore. Just look at the difference between fig 12 and the starting images! (and yes, the valve-cover changed to red.)

And, even after nearly six months of not being used, sitting in my frigid garage, the car fired on the first try with this battery. Very cool, and losing 30lbs for $100 is a pretty good mod in my book.