What would be the best ("highest capacity") battery to put into an 85 rx7?

I did a real quick search and read that the "VRLA AGM" type batteries sound like that they would be the best: http://uuhome.de/william.darden/carfaq7.htm#agm



My battery won't start my car at all in this shitty -30 Celcius weather...I had to leave my car at school overnight, and it still won't start! So instead of adding up the water levels in the battery, getting a boost, etc, etc...I'm just going to get a brand new battery altogether....what do you guys suggest?

 

I've been real impressed with my Optima battery.

 

I use a Interstate deep cycle marine battery in mine. Lots of power, lots of reserve and will charge back up to full capacity for those times i get a no start because of flooding or whatever. Discharging and recharging a regular car battery lowers it's capacity because they are not designed to go into deep discharge.

 

I went with a Optima Red Top type 35 battery.

 

I have heard nothing but good things about the Optima battery. I love the fact that it is a sealed battery so that you dont have to ever worry about spilling battery acid.

 

This website talks about the Marine battery...

http://uuhome.de/william.darden/carfaq7.htm#marine



Also the section where they mention Optima batteries, it really does sound like it's the best. I think I'm going to take a serious look at them:

http://www.optimabatteries.com/products/index.asp

 

If you got the $150 go with an optima for sure.. I am poor unfortunately but have been very impressed with Kragen's batteries. The one i have in my other RX7 I probably spent an hour or two (not all at once) trying to crank the damn car over while I was trying to figure out WTF was wrong with the damn ignition and that thing just kept crankin until I finally got it started like 2 hours of cranking and several weeks later..

Oh and ill add this warning just for the hell of it.. whatever you do DO NOT buy a napa battery, they are extremely poor quality and the lead inside the battery flakes off and settles on the bottom and over time enough of it collects to where it connects the positive and negative terminals and causes all sorts of electrical problems.. I went through 3 of those batteries, they kept replacing them free, and all of them had that same problem I finally just bought a different brand somewhere else.

 

Tried to edit, but too late. I got it at batteriesareus.com for $94 shipped. The best price I could find.

John

 

Optima Red Top, 900 Cold Cranking amps and power to spare! Never had an issue and battery acid and corroded terminals a thing of the past.

 

I just ran out after my last post to Cosco and bought it for $150. I can't wait to have it shipped anyways or I would've gotten it from batteriesareus.com.

Well, when I'm outta class (which will be in about 3 hours) I'll install my redtop and let you all know how it goes.

Btw, it's pretty damn warm out right now compared to what it was yesterday, and now the battery is completely dead...? All I need now is an alternator from a 92 buick lesabre and I'll be happy for power!!

 

You guys with the optima batteries, are you guys putting it in the stock location or relocating it to one of the storage bins?

 

Mine is in the sotrage bin, which makes that much more sense for a sealed battery.

I have a yellow-top, and so far, I am impresed. I had the car on jackstands for almosta year, and it started it on the first try. I never charged the battery all this time either.

 

now i am told about the napa batttery. i have one in my gs and one in my se. no problems so far. they do seem to die rather quickley though. hmmmm...

 

I installed the redtop, and it didn't start the car.


I must have flooded it last night and leaving it out in the cold overnight probably didn't help either.... After I installed the new battery earlier, it still didn't turn over and its flooded for sure now.

I'm gonna have to try the tech tips at http://www.rx7.com/tech/unflood-sa-carb.html to get it unflooded again.

I'm still going to keep that battery though!!!!!!!!!!!!

Thanks.

 

We use a Miata battery for the race car made by WeisCo or something like that. Its very small and light, and has been reliable for the last 2 seasons of getting beat around on the track.

 

I have the Optima red top...best purchase so far, specially since it's gettin chilly out....lots of tries before my rex starts up

 

I've had a Sears Die Hard Gold since I bought my car 6 yrs ago. I think they have the best replacement policy for my uses (limited to once or 2Xs a week driving). I just exchanged my old once last weekend, no questions asked, they just tested the battery and it was bad =).. no $hit... it was only sitting in my car for 3 weeks draining (been raining and never took it out). Last April I was near the end of my 3yr FREE Replacement guarantee on the Gold and had to fork over $32 (pro-rate the 100month warranty) for a NEW battery with a NEW 36 MONTH FREE replacement guarantee. Doing the numbers it comes out to about $0.90 a month for the battery. =) I like it b/c I don't drive my SE much now and I get a NEW battery whenever it's not up to par. Only fuss is driving 8 miles to the Sears. =)

 

Why is that? Forgive my n00bness...

 

Since the battery is in the passenger compartment,
I don't have to worry about Acid spilling out, and I don't have to worry about battery fumes.

If you have a regular battery in your passenger compartment, it should at least be in a battery box to protect you from the same effects I listed above.

 

that is a good idea! it seems more and more people are becoming engineering wizzes with the FB!

 

Normal batteries have wells in the bottom of thier cases to collect all the crud that sloughs off of the plates with time. When one or more of those wells fills up, the plates will short. The difference between a 40 month and a 60 month battery is simply the depth of these wells. When one of the wells fills up, you can get more life out of the battery by smacking it on the ground to loosen the deposits, then dump out the old electrolyte and refill the battery with fresh electrolyte. I've gotten up to two years of additional life from batteries that way.
Just a related anecdote.