I recently replaced my stock battery as it appeared to be leaking somewhat (a bit of corrosion on the top around the fill holes) and it has never had a vent tube attached (bought my car used).

My obvious choices were:
- Braille
- Optima
- Odyssey

I've had an optima before and it was great, but they're still lead acid and are heavier than stock Edit/correction: (it appears as if all optima batteries are advertised as being AGM now)

Odyssey is marketed more towards high reliability (AGM batteries) and I was about to go this route, but I also wanted to save some weight.

Braille has some great batteries available, and If I could grow money, I'd get one of their $2000 8lb lithium ion batteries. The next best thing is their no-weight AGM batteries.

I have an upgraded stereo with an amp and sub, so I didn't want a small battery, and decided on their largest no-weight battery (B3121) at 21lbs.

After a bit of research, I found that the braille's are likely re-badged deka motorcycle batteries. Their look, physical dimensions, and specs are nearly identical.

I found myself a new Deka ETX30L 21lb battery on ebay for $80 (these appear to be the same as the braille B3121 batteries). If you decide to get one of these, you may also need some braille battery terminals. These cost around $10 (search google). Normal battery posts that you buy at your local auto parts store will not fit.

This battery can be mounted with no additional hardware in a Z06. I used my existing battery strap. There's also now plenty of space around the battery so I have room to put my flat repair kit: (the silver stuff is my cheap sound deadening/insulation material)


The battery is advertised at 365 CCA, however mine has 400 CCA printed on the battery. The braille equivalent is rated at 550 CCA which means the Deka is under-rated, the Braille is over-rated, or they're not the same battery.

Regardless of what the CCA actually is, the battery starts the car with no problem (in 75+ degree temperatures).

Included with the battery is a voltage charge chart. As per the chart, these are best measured after the battery has been disconnected for 24 hours:

Voltage / Battery charge
12.80+ / 100%
12.60 / 75%
12.30 / 50%
12.00 / 25%
11.80 / 0%

After checking the voltage each day during a week of daily driving, my battery has been between 12.65v and 12.75v with the car off and while the battery is connected to the the car's electronics. It is keeping a charge with no problem so far. I do not use a battery tender and never leave the car off for more than two days.

So far, it has worked out great, though of course I'll post again if I run into any problems.

There are many advantages and some disadvantages with going with a smaller AGM battery. Read more about them at http://en.wikipedia.org/wiki/Absorbent_glass_mat
The main advantages for me are:
- ~10lbs less weight
- Less space used
- no chance of acid leaking

In other news, I've seen AGM motorcyle batteries for sale at wal-mart...
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BATTERY LIFE UPDATE (DEC 4, 2011)
After about 14 months of use, driving 4-5 times per week, the battery failed to start my car today.

For the past few days, it had trouble starting it. The starter would activate, but for less than a second and the car would shut off (and reset the computer like the battery was disconnected). Another attempt would then get the car started.

Though today, after two days of not driving, the starter would only click once. When measuring the voltage of the battery with the car electronics on (engine off), I was getting 11.6v (dead battery as per the above chart). I actually jumpered my previous lead acid battery to it and started the car. I'm surprised my old battery lasted so long with no use.

Now hopefully the 20 minute drive to work was enough to start the car for my drive back. May have to skip on the weight savings and put my lead acid battery back in or look for a bigger AGM battery (odyssey looks good)

 

http://forums.corvetteforum.com/c6-t...tall-pics.html

San

 

Are you sure that one is labeled as a Braille battery?
I think you might be talking about the XS Power line of batteries.
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I went with the 21 pound Braille vs. the Deka. Yea I paid more ($161 delivered) but with the 550 CC rating I didn't want to take a chance on the lower rated even though same size. The terminal posts are included with the Braille so a little saved there with your $10 plus shipping estimate.

I've had it in a several months now without any problem. Really all you need is enough power to start the car. Once started the alternator takes care of those stereos and other accessories. Of course you want a battery that will still start after the car may have set a couple days without usage.

This is how I mounted mine. I used a piece of aluminum rectangular bar I already had in the garage and bought two wing nuts and an all thread rod whick I cut two pieces.

By the way, my factory battery weighed 34#. A 13 pound savings.

 

Nice! I didn't even see that when searching around for dekas in corvettes


The ultimate braille batteries are lithium ion and are about $2000 each: http://www.braillebattery.com/index....teries/b128l/# I don't know much about XS batteries, but they also appear to be lightweight AGM racing batteries.

Nice to hear! I don't remember where, but heard something about these batteries (deka/braille) not liking a constant high voltage (14.6+) from the car's alternator and dying prematurely. Hopefully that was just a one-time thing..

 

I don't believe the problem is voltage, I think it's the amperage of a car's charging system that kills a 'motorcycle' battery. My 15 lb Braille barely lasted a year, probably because of this issue.

I now have a 21 lb Odyssey PC925 and was guaranteed this charging thing will not be an issue because it is a battery designed for a car. It also turns the engine over way better than the Braille ever did.

As a test, one night last week when I was working on the car I kept the radio playing for nearly 4 hours straight (PITA because I had to turn the acc. back on every 1/2 hours) but the car still started when I was done.

Cheers, Paul.

 

14 months later, the battery appears to have died - updating my main post

 

3+ years later and my Deka is fine.

San

 

I have really been thinking about doing this!!!

 

Seems kinda risky for a small frame weight advantage. I'd rather have some strong CCA available all the time.

 

I agree 100%, and besides, taking weight off the rear of a Z alone is not the best choice, IMO. If you could shed weight off the front as well, then it would make sense. Not sure I see the sense in taking weight off the rear alone in a traction limited car like ours.....

 

If you could use a smaller battery, GM would becasue it would save weight and cost. I use an Optima yellow 35 and it has gone strong since the day I bought the car new Christmas 2005 (I changed it the day I got the car).

Smaller is great for a race car, bigger is better for a street car.