My battery is already relocated into the passenger bin , But I was using a second Gen miata battery , the car started But I had to swap batteries as starting the car would kill the battery very fast and it would only ever spin 180 rpm , instead of the 250 needed .

the miata battery had 370 CCA , I figured one of the 51r's would fit in the bin in my trey I made form a boat battery . But the deep cycle optima's will give consistant power longer so even though its only 450 CCA it will give 450 CCA for a longer time ,

While the Regular batteries although higher CCA 500 the one I looked at . will do 500 for the first 5 seconds , and then slow down drastically ,

since my motor is fresh the miata battery spinning at its whopping 180 and going to 160 in seconds is making it very difficult to deal with .

as I'm trying to tune the startup fuel map. and driving around with a car that may or may not start is just stupid .

I would like something that will start period . so thats why the question on what people suggest . TY

Not rocket science
 

I have been using a lawn tractor battery in my FD for about 10 years. It starts fine, runs fine and costs about $25. I use one because my custom intercooler takes up most of the allotted battery space. Just make sure the positive and negative terminals are in the right place for the car. I would give you a part number but I remove the decals from the battery's for a cleaner/neater look. Each battery has lasted me about 3 years. My cars are all parked in the winter with batteries fully charged then disconnected. Originally I looked at the dry cell batteries.... They are 2 pounds lighter but cost WAY more. If you are worried about the 2 pounds... stop eating at McDonald's.

I'm more worried about my car starting when I want it to , My current battery only spins at a whopping 160 rpms tgo start and just left me high and dry half a block form home .

so tomorrow I'm off to the battery shop .

I have an NB miata battery , with its whopping 370 CCA it just isnt cutting it . car is a fresh rebuild just put the first 30 miles on the motor , and it takes a bit to start up because its only spining at 160 , alt is charging at 13.7 and has been rebuilt .

Ive had problems with this battery before . I just want something that will start when ever I tell it to will spin and wont leave me high and dry because it had to spin a bit more then usual . that day .

I think I'm going to go with the deep cycle because it will give more consistant cranking .. since I'm still working on the start up tunning I think this is the best option

I am using a westco miata battery has 475cca.

I run these in my bikes. I wonder if they will work in a car.
http://www.ballisticparts.com/index.php

+1 for westco miata battery. Been working great for me for three years so far. Although I can't let my car sit for more then 3 weeks or the battery drains out haha. More incentive to drive it every weekend!

What miata battery is it ? the NC miata , Or NB/NA miata . I just purchsed a battery The http://www.autozone.com/autozone/acc...er=605893_0_0_ , But I think I may have over done it with the size..

this is actually the correct battery for the car. But i have doubts it will fit . So I may be returning it and trying a 51R . if it doesnt fit . plus its 10 lbs heavier haha .

Well if this fits I may just keep it if not I'm gonna give the 51R a try

I have the NB AGM battery from Advanced, same as the Westco battery.

Where did you get the Miata battery?

Advanced auto same

Mine is for a nb.

Westco Mazda MX-5 Miata Battery 1990-2005 - SALE!!!

More expensive but very good:
Braille Battery USA &nbsp&nbsp&nbsp&nbsp Lighter • Stronger • Faster

I believe Braille is just rebadged Deka, you can order from Deka directly and pay less. Same goes for the Miata battery, Westco, Marathon and Advanced are all from Deka.

Damn that westco battery ...... that looks very good ... I already purchased an optima and honestly its been behaving very well , even with some flooding issues I've had . I cant complain . I would of gone with a westco.. If I didnt have to order it . if I have an issue with it . I can throw my battery at the autozone people and get a free replacement. But for that price difference I think it might of been worth it ..

I have experience with the westco, optima 51r, and braille 3121.

Westco: Cost: $120 - Fits perfect, no cutting required, not enough reserve to crank car after sitting for too long, AH kinda low compared to others. I'd recommend if you had no gauges / audio.

Braille 3121 (Friend is using this one): Cost $217 - Fits perfect, no cutting required, problem for me is that this might be a rebadged Deka EXT30L ($100) and Deka's rating for this battery is much lower than that of the Braille 3121, so if rumors are true, Braille is being unethical about this and I wouldn't support them (unless the battery costed $100)

Optima 51R: Cost $150 (friend helped me out) Just put this one in, thought it would fit in the bin if I melted the bottom of the bin but eventually had to cut it to fit everything in. Currently using this for a 20b w/ haltech ps2k, afr / boost guage, no audio yet.

Alternator plays a more important role, so lets go bother IRP for an alternator group buy.

off topic sort of - but i recently jump started my FD with a 6s lipo battery from my RC helicopter (its about 26volts and would be about 1/10 the size of a car battery)

yea bad idea, but i was stuck and it out worked fine. turned the car over easy as and i didnt blow anything up :lol: :icon_tup:

I've used a DEKA ETX18L AGM 340CCA (just noticed they are $73 on Amazon) for a long time. I'd say this about running tiny batteries.

1. Get a tender! You'll probably double or more the useful life. There is just enough length to pass this one through to the front bumper. So you can just plug it in without opening the hood.
2. It's going to probably last half as long as one twice the size. Maybe 2-3 years.

3. it will start fine and work great day to day, but, if your car is having issues, you only get so many retries... so really I wouldn't do this unless you have a reliable car.

Not entirely a bad idea, I have seen on clublexis and also hondatech people made DIY lithium ion batteries for their cars. I looked into it but it is my understanding lithium ion batteries are very sensitive to charging voltage. one of my coworkers is a phd in electrical engineering im going to see if he will help me make a battery/ charging controller.

So question everyone.

Does this have enough CCA at 380?

OP, I know a guy selling a turbojeff battery tray. I can get you in touch with him if you want. PM me your number and I will have him contact you.

Yes.

FWIW, my last PC925 lasted about 10 years in my FD as a daily driver, with the battery located in the rear bin. After researching a number of other AGM replacement batteries, I bought another PC925 because it is more tolerant of charging system conditions and variations--and it never left me stranded.

*Important note: the lifespan for ANY battery located in a FD engine compartment will be substantially reduced due to heat stress.

Thanks Speed of Light! Interesting. Might be why my current battery when it was able to be charged only lasted a week.

Don't spend that much for less CCA, plus 1 extra pound of weight.

Westco 12V31M Miata Battery for Miata

How Low Weight Can You Go?
 

I'm Just exploring the lower limits on my FD battery, which for the most part sits in the garage in Southern California with a trickle charger attached except for club, track, or autocross events. The main drawback to this 210CCA battery is after 4 days of sitting unused without the charger attached the alarm will drain the battery enough to make for iffy starting. I just got back from 3 days at a VARA event, without the charger, at Buttonwillow Raceway and it worked like a charm.

https://cimg8.ibsrv.net/gimg/www.rx7...894cb2128a.jpg

So, for the ultimate in low weight (1.5 lbs) this lithium iron power sport starting battery seems to be the solution for me.


https://cimg2.ibsrv.net/gimg/www.rx7...e3dad4ebb4.jpg

Odyssey
 

I have a PC-925 in my FD. It starts my 7.0 Liter LS3 just fine.
It has 925 cranking amps at 32 degrees f.
CCA is 330 at 0 degrees f, in which case I'd be driving something else anyway.

I have a PC-1200 in my Cobra. The first one lasted almost 14 years on a Battery Maintainer, until it finally wouldn't spin the 12.5:1 427 big block anymore. :tightass:
They aren't light by any means, but for a street car the reliability can't be beat.

I use the biggest of the Shoria Lithium-Iron batteries.

540 CCA and weighs almost 5lbs.

6.5"x6.5"x3.5" and does not need much to mount it if you can get the tech inspectors to realize its only 5lbs.

How has the lithium battery held up so far?