At five years I figure it's time to replace the battery before I get stuck. I never thought figuring out the battery size would be so difficult. The coupe and sedan may have different sizes and the manual does not list size. Does an '08 G35X Sedan use a Group 35 or Group 24F? Also, the local dealer wants $170. I'm not handy and it appears a battery change on the G is more difficult than the typical disconnect and drop in. Can I trust Auto Zone, Advance Auto, Pep Boys etc with the free installation? What annoys me is all of their websites do not distinguish between coupe and sedan and all say Group 35 but I'm not sure.

 

https://g35driver.com/forums/v36-diy...r-battery.html

Courtesy of Soundmike

 

you can definitely change it yourself. Just follow that DIY. i would NOT trust any of the shops you mentioned to put it in for you. They'll break clips with wanton disregard.

Pepboys has a printable $20 off $100 coupon on the website, expiring 3/31- their size 35 battery is a bosch, which comes down to $100 after the coupon. Spend the $70 on something cool

 

I got the 35 Durlast Gold... Boy what a difference when starting...

 

I got an interstate one that just barely fit because of the running of electronics (3000 watt amp, gps, charger, etc) and holy jesus what a difference, however it JUST barely fits lol

 

DIY bro.... The guide here by sound Mike rocks. Cant tryst n e shops.. No one cares about other peoples property these days. Get ur self a nice costco battery.... U can return it n e time for a full refund

 

I noticed the other day that Costco's fitment book calls for a group 24F for our cars; so I guess they will accept either a 35 or a 24F. AFAIK, the 35 it a tad shorter, but slightly fatter and maybe taller than the 24F. I also noticed that the CCA rating of their replacement is way higher that the OEM battery was. No worries though, as I'm STILL chugging along just fine on my OEM battery as it nears the 7 year mark here in just 2 months.


BTW, the current price on the Costco batt was something like $78.99 + $9 refundable core charge.



EDIT: After further checking, the current Costco book incorrectly lists the '07 as a group 24F. There older book does show it (as well as the '08 sedan) as taking the group 35.The god news is the price is only 73.99, not 78.99.

 

^ Did you look at 2008 Infiniti G35 sedan? When I bought my battery using Costco's book for a 2008 Infiniti G35, it was a group 35.

A 2007 Infiniti coupe uses a group 24, which is why it's confusing to use 2007 Infiniti G35 for parts. It is much easier to use 2008 Infiniti G35, as there is no 2008 Infiniti G35 coupe.

 

See post #4. I also went with the Duralast Gold 35 series and never had an issue whatsoever for the past year now. My advice when buying a battery is to go for the one with the longest warranty and check how long its covered for the free replacement vs prorated warranty period. Then factor in price and brand. If money is no object, get an Optima yellow top.

 

Yep, I sure did. Having an '07 myeslf, I learned all too soon that it was better to always say it was an '08 so there was no confusion between coupe and sedan. In this case, it was listed for: G35 2007 - '08 SEDAN

I do have to swing by there again soon though, so I will double it check it just the same.


EDIT: OK, FOLLOWING UP HERE: So I was totally wrong about what the (current) book said. I misread the listing apparently. In fact it said G35 2007 - '03 SEDAN, and there was no listing for a '08 sedan . I made them pull up their book from last year and it correctly showed it as a group 35, and it did list the '08 sedan. But again, their latest book has no listing whatsoever for a 2008 sedan.

 

Just bumping an old thread to clarify for folks a bit. Our cars apparently can have either a 35 or 24 sized battery depending on maybe when they were produced i guess... I'm not sure why but i'ts what i suspect.

FWIW - I just replaced my original battery (Shocking that it held so long) yesterday. The Napa book on an 08x sedan called for a group 35 battery, but when I removed the OEM battery, it was a group 24. I replaced with group 24 and it fit like a charm + started right up.

 

I thought it was a 35 but the 35 did not fit, I had a 24 in the car (I thought I had a 35) and the new 24 fit. I guess it's a 24 after all - it's very confusing.

 

FWIW, my sister had the battery replaced by her Infiniti dealer (with an OEM battery) and the part # is listed as 999M1-QC24F.

I bought the car ('08 G35X) off of her and she gave me all of the service records.

 

most shops gave me wrong advice

 

Every "battery selector" I tried after posting the above indicates the battery size is a # 35.

Just checking dimensions:
Length Width Height
10-1/4" 6-13/16" 9" 24F
9-1/6" 6-7/8" 8-7/8" 35

So while Infiniti specs a 24F, it looks like almost all aftermarkets go on the safe side and spec a slightly smaller case. A 35 will fit (I really doubt that being 1/16" wider will present an issue).