It was the best of times, it was the worst of times....

2013 G37 Vert -- a month or so ago my car wouldn't start. The battery was 3 years old, so I went to AutoZone to get another Duralast Gold (35-DLG). Installed the battery, Reset the windows, reset the seat memory, and ran the top open and closed to reset that. I noticed the car doors wouldn't open unless I got right next to them. I had the same issue with the trunk. I put a new battery in my key fob with no change. I swapped to the other key fob and put a new battery in it, same issue. Not the fobs, must be the car. Oh well. At least I have a brand new main battery in the car. Two weeks later, car won't start. Took that bad battery back to AutoZone for a swap out. Upgraded to the Platinum (35-AGM). Installed that one, finally done with this battery nonsense. Two weeks later, car wouldn't start. I was convinced it was the car. Must be some parasitic load. I did measure some parasitic load (400 ma or so), and it seemed to be the top. I jumped the car and ran the top open and closed, drove around for 30 minutes, Next morning, car wouldn't start. I took the car to the dealer to let them troubleshoot the parasitic load and fix this once and for all. They tested my battery and it FAILED. DCA-8000 said to replace it. Okay. So, I paid the dealer $199 for the battery (AutoZone's platinum was $249), and I paid them $105 to install it (whatcha gonna do?). I was not convinced this was the problem. I just knew I didn't get two bad batteries in a row. Well, here we are 1 week later and everything is still okay. I think I really did get two bad batteries in a row from AutoZone. Plus, AutoZone's website recommended a group 35 battery (which I had been using for the last 3 years), but the dealer put in a group 24F. The 24F has more CCA, and it is cheaper. I'm convinced that the other batteries were not holding charge and the reduced voltage was letting the convertible top controller lose it's position, which prevented it from going to sleep which then was a parasitic load that continued to drain the battery overnight. So, what about the key fob? Now, with a fresh, new battery, the door locks and trunk open fine without getting right up next to the car. I think as the battery voltage was getting low, it somehow degraded the reception of the sensor in the car that detects the key fob.

What did I learn? Don't buy a battery from AutoZone? maybe. Use a group 24F for my vert instead of a group 35 - probably.

 

Yep, I think a lot of vert owners went through a similar fiasco, unless they looked on the forum and got a 24F right away.
It was a bit more difficult to install, but well worth it - no issues whatsoever.
I got mine from advanced auto with 3y warranty.

What's interesting is that the second battery on my mazda (same gold, but size 35) went bad after less than 2y. Luckily it was replaced for free. Let's see how long this one will last.

 

That's pretty interesting I run a 35 on my engine stand but everything shuts off.
We run a larger marine one on the VHR drift car that's a trooper but everything shuts off.

I wonder how many Coupe/Sedans could benefit from a 24F just like Verts.

 

I'm no battery expert, but I think the group size (35, 24F, etc.) is more about the dimensions than the capacity. The 24F is wider than the 35. I remember thinking I had a lot of extra space when I had the 35 in there. Perhaps because of the larger width, it seems that the 24F size of the similar battery class has more CCA. (i.e. - Duralast Gold 35 - 640 CCA, Duralast Gold 24F = 750 CCA) But there are 24F's with lower CCA ratings. The dealer battery they gave me was an Infiniti 999M1-QC24F which has 700 CCA.

 

Differences are cell height and width.

In theory wider cells should produce less drainage, taller ones I believe higher CCA

I'm convinced the G/Z need something in the 700cca + to survive decently. In my experience the starter consumes quite a bit of amperage and when it fails to start it slightly hurts the battery over time. You mix this with slow draining issues and you might kill a battery if too many failed starts happen.

 

Yeah the G37 came with the 35 to save Infiniti some $$$. The M37 came with the 24F. When I first went to the larger 24F I noticed the car started and shifted gears faster and holds a charge longer.

 

I've had similar problems with DieHard batteries from Autozone. Two year warranty on my G37 Vert, failed at 28 months. Replacement on my Subaru failed at eight months. DieHard is not what it used to be. I just read on Reddit that Duralast and DieHard are made in the same factory. Trying out an Interstate battery now from Costco. DieHard lost a 30+ year customer.

 

Do not do Costco. I got about 8 months out of it and their warranty sucks. Its pro-rated from day one. Best deal I found is Exide SPRINTER MAX from home depot. $129 3yr free replacement. (plus my no tax code=WIN...for me) Reviews are good although the warranty process might take a few days (deal breaker for some)VS same day from other stores. Walmart used to be my go to. For $97 3yr free- 5yr pro-rated they lasted exactly 3yrs. Now they're 3yr free replacement for $149. Still, not bad.