I had one optima just to run the four compressors I used for the air ride suspension :D

 

Thanks!!!!

 

I would strongly recommend getting the proper reverse terminal battery. Lengthening the positive terminal to fit the 75/35 battery does work, but it introduces more points of electrical contact and more points of failure. Not to say it doesn't work, or you would ever have any problems with it, but I just like a nice, clean installation. Being able to easily buy the right battery online and pay a little in shipping, there's no reason not to.

Dale

 

not really.. 1st now I have a permanent Aux Pos (+) Post to attach extras. 2nd the battery is now much easyer to get out of the box becasue the pos lead will now move


Anyway as an electrician I can tell you that adding the copper lug like i did and the extra 2 inches of cable will not add any signafigant resistance at all!

So again .. dont let this stop you from getting that Red top at Costco for 99 dollars. or online for 79.. if you can find the other one !! than by all means get it .

p.s. if you do find the grp 35 please link the online seller here..

thanks again

happy Zoom - Zoom

 

romulus,

Thanks for pointing out the existence of the Optima RedTop 35 and the URL you provided - $94.95 delivered, no tax outside Nebraska.

When I replace my battery (stock battery working fine - no need to replace it yet), it's going to be with a group 35 which should drop in perfectly with no extra costly hardware required since I don't plan on hanging any "extras" off my battery, the posts are correctly positioned, and I prefer a clean, stock-looking install. I'm not sure if it will be an Optima.

rx8cited

 

rx8cited,
You are welcome!

 

Q: Was there any weight savings between the stock and the optima?

 

OK, I searched first before posting about Optima batteries.

I just wanted to record the fact (with pictures) that there is an Optima that fits the RX-8 with *no* mods to the car wiring harness. It has to be the model 34R Optima battery. This is the "reversed" terminal one mentioned a few times. Yes, it fits. Items used:

(1) Optima model 34R battery
(1) Optima AD24R battery tray - to raise the overall height

Below is a top view of the battery. Note the slight clearance around the edge toward the passenger side and toward the front.

 

This is an offset view of the battery in the tray, just for further clarification.

 

OK, and now, for completeness, the stock battery cover is in place. I did not really need to include this one, just being sincere (and compulsive?).

All this was done just so someone else who uses search will be able to find this thread and *see* that it fits with no electrical changes whatsoever.

Also - I am a big fan of Optima products. I broke the alternator belt on my RX-7 in Chicago, IL in rush hour. I drove all the way home to Kalamazoo, MI with an Optima 75 (the smallest one they make) as my sole power source for the ignition, etc.

 

I totally copied you and am very happy with the Optima battery "mod". Thanks for posting these instructions.

 

Good info.

How much did you pay for this battery?

Based on my measurements, the Optima group 35 battery should also drop in with no nasty extenders required. Did you consider that one?

Consider posting your info in https://www.rx8club.com/showthread.php?t=33340 as it's relevant.

rx8cited

 

It was requested that I post this reply here. The other thread has info that may be of interest. I apologize for the new thread, I thought it needed to stand on it's own for search purposes. Anyway:

https://www.rx8club.com/showthread.php?t=38452

Answers:
I paid $151 for 34 R battery and tray. I am sure you can do better.
The Model 35 should work also - smaller, 4 lbs lighter. Then again, I would rather stuff the battery envelope with all the watts possbile -
Scotty: "I'm givin' it all she's got, Cap'un!"

 

yes and when i put mine in that was all that was offerd

 

Where did you buy your battery from? Do they now sell the 34R or 35? I found that Sears, Costco, and Pep Boys did not stock those models.

rx8cited

 

i got mine at costco .. thats why i did the mod because it can be found here.. but i understand it can be bought on the web now.

 

Yep, one can get them RX-8 friendly battery models on the web or by calling a battery dealer in the yellow pages if in a hurry.

rx8cited

 

Better yet use this battery and not modify anything. Way better than an optima and it's a true deep cycle dry cell with a 6-10 year service life. And 1200 cranking amps for the 1st 7 seconds, very low internal impedance.

 

As a point of reference to those who may come upon this thread in the future; a Service Bulletin from 12/15/2004 describes a design feature of the battery system which requires clearance between the battery and case. Cool air is ducted around the battery inside the case to reduce the temperature experienced by the battery. A battery that is physically larger than stock could reduce or eliminate the cooling and result in reduced life.

http://www.finishlineperformance.com.../01-042-04.htm

 

I disagree ....... in the case of the manual transmission anyway.

There's plently of extra room in the stock battery box to put a battery larger than my stock battery. The important point this Service Tip is making is that the battery box and cover are required and that the front of the new battery should be positioned the way they show with respect to the white painted area to allow for airflow ..... probably no further forward.

I bet the new MT RX-8 battery is a group 35 while the original stock battery is smaller.

If I need a new battery today, I'd buy a group 35 (which is not the same as a 75/35 battery BTW) as I took measurements months ago and know it would fit with room left for airflow.

 

Well, I just bought an Optima red top Grp.35. I will install it soon.

 

Has anyone installed one of this model yet?

Does it require the height adaptor to fit in the RX-8? <http://www.batteriesareus.com/shop/product_info.php?products_id=116&osCsid=287177d532 0f94ca136359a1637b1a65>

 

I will be installing one on friday. I do have the hight adaptor just in case i need it. I will post pics.

 

Just got done! It did require the height adaptor. No more 300CCA for me...Now 720

 

Cool - thanks!