psonoda

I have started my zero weight project. (Adding lightness to increase performance) One of the first projects is replacing the factory battery with a ultra-lightweight battery. Here are some pictures of the project in process. I still need to make a bracket to hold the battery in place. But for the moment, the battery in snug and doesn't move.

The weight savings is 23 pounds (battery alone) plus the removal of the battery cover, terminal connectors and battery side housing. Let me know what you think.

Optical TDI

iTrader: (2)

I'm in Ohio too. Will that start the car in the winter? Please post other weight savings ideas you have as well. Thanks.

psonoda

I guess we will see. The battery has 800 cold cranking amps. And overall higher specs than either stock batteries. I am keeping the stock battery in case i have a probelm. The way I did this, it is relatively easy to return the battery back to stock.

nycgps

iTrader: (1)

800 CCA? really, Any links to the full spec of the battery ?

TeamRX8

iTrader: (25)

check out the search function instead

psonoda

Here is a link to their site. I have been told that the rest of the specs are better than stock. However, I do not have those specs. There were not included with the battery. As soon as I get them, i will post them here.

http://www.batcap.net/800.html

nycgps

iTrader: (1)

lol ! Aye ....

SEARCH NOOB !

Go48

It is probably telling that they apparently don't provide the specs on their web site. For example, the Interstate battery web site provides complete specs for all their products. And since this apparently is a capacitor vs. a storage battery (that is not clear from their one-page description), I would be concerned about the ability of it to support recovery from flooding. That is, repeated drainage of the capacitor without recharging. And, can you use a battery charger to charge the capacitor? Dunno!

BTW, my guess is that the way they cite the capacity, "...800 peak amp!", that is probably not the CCA rating, otherwise I would expect that they would have stated 800 Amps CCA. But I could be wrong. Look forward to seeing the detailed specs.

alnielsen

iTrader: (4)

This is from http://www.lightav.com/car/batcap/batcap.html It provides a little more information.

It looks like it was meant to be an aux battery. Not a starter battery, as you are using it.

Go48

"20 Ah Reserve Capacity
800 Cranking Amps"

Note the original RX-8 OEM battery ratings in the shop manual page attached. For "normal" climates it was delivered with a battery rated at 40/48 AH, and for cold climates, the rating was 52 AH, so the BatCap "battery" at 20 AH reserve may not support the repeated engine cranking cycles required for flooding recovery. In addition, the original OEM battery was replaced under a service bulletin by a more capable battery. So, the 40/48/52 AH was not even adequate when called upon to crank the engine during flooding recovery.

Also, Cranking Amps is not the same as Cold Cranking Amps, although the rating for this battery probably would have an acceptible CCA rating which obviously would be something less than 800.

Nubo

Just speculating, but I don't think this battery is built on capacitors, not with 20AH capacity.

I would guess it's using cells with low internal resistance, such as Ni-Cd, NiMH, or LiPO. If the latter, then you'd be well advised to carry a fire extinguisher.

Or, maybe it's just a baby lead-acid with a big cap, to provide those 800 amps (but very briefly).

Also, you'd be better off retaining the old battery housing, as it does allow some cooling air through the case to keep the temps down. Probably worth it for a few ounces of plastic.

psonoda

Thanks for the feed back guys. I have a little more information.

I spoke with the owner of Bat Cap. He was quite helpful. Here is what I learned.

• The 800 has a peak output capability of 800 amps for about 5 seconds.
  
• The actual CCA as defined is about 400
  
• Cold Cranking Amps testing is defined by the amount of current available at 0 degrees F for 30 seconds.
  
• The 20 AH rating was measured using the 10 hour rate or 2 amps and hour for 10 hours. There are two standard tests: 10 hour and 20 hour. Using the 20 hour, the results increase to 25 AH
  
• The ESR (Equivalent Series Resistance) is extremely low at 3 milliohms. That is in the capacitor range.
  
• The Duty cycle is where the battery is impressive. Standard batteries have usually are designed to take 300 cycles at 10% draw with about 60% of the battery performance left. The Xstatic 800 is rated to handle 1500 cycles at 30% load with 80% battery performance left. My understanding for this is the low ESR and the construction. The 800 uses virgin lead while many batteries use recycled lead. The challenge with recycled lead is filtering out impurities. The result is a battery life of around 10 years with proper maintenance.

So basically it is a well built baby lead-acid sealed battery.

I plan to add a bracket over the top of the battery to ensure it cannot move. Also I plan to get another battery mounting base plate to modify to further reduce weight.

Of course, I have saved all the connections so that I can return to stock if I have any problems.

nycgps

iTrader: (1)

That is exactly why I post this b4.

After that post I google it and found the site.

It saids 800, but it has no words about CCA anywhere on the site (not even the full spec)

rotarenvy

I have a similar battery fitted (may even be the same one re-branded). it has started the car fine for about a year. even with short re-charging drives and rotary starts (cranking for ages) it has never gone flat. I have had the car off the road for a week and it still started fine. the only time I wouldn't fit one of these batteries is if I had an after-market alarm fitted or subs and amps in the boot.

psonoda

That is great to hear. So far, I have had no problmes. In fact, it appeared to be getting stronger. (It was sitting in my garage for a little while). I am still working on tie down. However, my car is in the shop right now.