My battery died without any notice or warning. I want to use this opportunity to lighten the load a bit and get a lighter battery without compromising reliability. The OEM battery is HUGE and has 550 cold cranking amps (CCA). The specs call for 525 CCA. I bought a battery - Duralast model #51R-DLG that is 500 CCA and 625 cranking amps and weighs only 28 lbs. I saw a battery there that was even smaller but the CCA was way to low.

These pics show the difference in size.




Does anyone know the weight of the stock battery? I bet its 40-50 lbs.

 

Here are pics of it installed. It makes teh engine compartment seem much more roomy.




I used the stock clamp and it holds it well.

 

I turned the headlights on and AC on and the car started right up. I imagine the car will feel lighter when going hard in a turn with about 20 lbs less weight in the very front of the car. The polar moment of inertia has to be reduced significantly.

 

I don't think 20 pounds would make a difference on a 4500 pound car? But I could be wrong.

 

You're throwing a lot of jargon out there......there's no need for all the "polar moment of inertia" talk. 20 lbs without any other weight reducing mods isn't going to make a "significant" difference in turning or acceleration to be noticeable. Good job cutting the weight though.

 

Curb Weight: 3,436 pounds

His exhaust, wheels and other items that he has changed are lighter than OEM parts. Deus also runs auto-cross and would know if there is any difference good or bad.

I had my car weighted at a truck weigh station awhile back and it weighted 3305 lbs with my mods at the time.

 

I figure every little bit helps. "Polar moment of inertia" is a fairly simple and very relevant concept. Essentially it means that it takes more force to rotate an object around an axis when there is more weight furthur away from the point of rotation. More force means less responsive handling. An easy demonstration of this is to take a ratchet and put a large socket on the end an rotate it like its a car going around a turn. Now take a much lighter socket and put it on the end and do the same motion with it. U can clearly feel the difference. FYI.

 

With the way you drive autocross (since 666 is your number), I'll bet the reduction will help out. I wouldn't be concerned about the reduction in CCA unless it gets really cold in the winter where you are. I don't know anything about the weather in CA.

 

It will help, any weight loss will. Let us know how that battery holds up, I weighed the stocker a while back and I think it was around 50-56 lbs, maybe in the 40s.

 

I figure the stock battery weighs around 45-50lbs. If someone wants to be a good guy and measure it, that would be great. Measure it with the battery cover too since I took that out as well.

The weather here in so cal is almost always warm. A few times a year it dips into the 30's but not often, maybe a dozen days out of the year.

 

I bumped mine up and dropped in a 675 CCA battery from Batteries Plus. Cost was like $65...and they install free in case you're lazy.

 

I got my stocker sitting in the garage (for sale too.. it's brand new.. anyone want??? ) ... let me see if we have a scale.

 

the braille ones are 15lbs. and can stand up to normal use. probably couldnt use it if you have a sound system. yeah the stock battery should be up there about 45lbs.

 

I don't have a scale, but I checked online and it seems to be between 45-49lbs... my optima redtop is 39lbs though..

-edit- actually, I think I looked at the wrong optima.. mine's actually 33lbs.. it's smaller though, but it has plenty of power.

 

I know Braille and Odessy make batteries but they are about $120-$150 I think. They do weigh about half of what mine weighs. However, i dont know if they are for day to day use. I figured mine was a good compromise. I drop 20 lbs and it will likely last under day to day circumstances.

 

wow d00d

 

http://forums.maxima.org/showthread.php?t=501556

Good choice. 20 lbs lighter is like getting 2 free HP.

 

I think this is pretty light...............................

http://www.forgedinternals.com/store/home.php?cat=291

not sure how the power and all would go with our car, but possible ?

 

It is but the CCA is quite low. It would be great for racing though.

 

So what would be the downside(s) of that battery? "Bad" under what conditions?

 

Hehe, always on a lookout for deadbeat weight. Good one Deus.

 

Reserve power differences?

 

Higher polar moment of inertia?

 

A very small battery may cause a bigger voltage drop during cranking. The whole starter cuircuit could take a beating over time with the wires heating up too much. If voltage drops too low, it may impact the ECU and the spark plug coils. Service manual says above 32F, the minimum voltage during cranking should be 9.7 volts.

But the 11 lbs B14115 Carbon Fiber Braille shows a Pulse Cranking Amps Over 900. WOW. That is probably your best bet for the track.

 

But not for daily driving or winter driving?

 

One common theme I read is that smaller batteries do not have the 'reserve' to survive continuous discharges. Winter driving with lower speed and lots of power hungry accessories running full tilt (rear defroster) drain the battery. If you spend enough time driving on the highway, then the battery (small or large) will fully recharge. But, city driving will cause the half charged battery to fall victim of sulfation and one morning unable to start the car. A larger battery operating at 90% charge will survive this condition for a much longer time. I think Deus has the best compromise for the street. IMO.

I have a 26R-5N with an underdrive pulley. At idle, my blower fan does slow down. I touch the gas pedal, and the speed almost doubles. I have not checked the voltage but, at idle, the battery is probably not being recharged.

 

hmm.. my friend has the braille CF battery on his altima SE-R. he had it for a few months now, and he drives the hell out of his car, and no problems yet. we drove through highway, rush hour stop and go traffic, all with AC on and with radio on. but no problems yet. we'll see how long his battery lasts.

 

I considered an Odessy or Braille. They are 50-100% more expensive and you save anotehr 10-15 lbs. I would need to make my own battery hold down - especially for competitions. Speaking of which I have a night autocross Im going to do on Saturday night. Hmmmm. . . . . I think I'll start a thread on it for local 6th gen people.