Anybody tried using a group 34 battery in the coupe, rather than the OEM group 35? I think it will fit, it's roughly an inch longer (10.5 vs 9.5) and quarter inch taller. Width is about the same. for this, you get 750 CCA (vs. 680 CCA) and 120 reserve min (vs 100). This might be at least a partial solution for the infamous G37 battery drain headache.

Even with a new battery, mine is slow to crank over in very cold weather and I feel like I always have to carry jumper cables and/or a jump battery, which is not something you would expect with a higher end vehicle.

 

dealer installed the battery for the m when they did the battery drain recall.

 

Yes it will fit. I also have the battery from the M. However the larger battery itself is not the fix for the battery drain issue. Fix what's draining it.

If your battery is barely starting the car, you have a problem. Either your batter is bad or something is draining it or your alternator is not doing it's job. What is your battery voltage when the car is off and when it's running?

 

Understood, thanks. I had it tested by infiniti a few years ago, and they installed a new battery at that time. I have since had it tested at a Nissan/Infiniti specialty shop in town, they gave it a clean bill of health. As long as it's not sub-freezing and I drive the car daily, I have no problems. Let it get cold tho and it's a different story. I run a Duralast gold, it's nearing 3 yrs old so I figure I'll swap in the larger battery before winter this year.

 

Pick up a battery hydrometer and test all 6 battery cells while the weather is warm. They cost about $10.00



You can also pick up a cheap voltmeter at Harbor Freight or Amazon also about $10.00

The voltage across your battery with the engine off is 12.6 volts
With the engine running and the alternator charging the battery you should observe a 14.4 volt reading with the voltmeter across the battery terminals.

If one or more cells do not come up to a full charge then it is time to replace the battery.
On my previous 06 G35 the price of a 700 CCA battery at the Infiniti dealer was only a few dollars higher than other shops so I had the dealer install the new battery.

All my presets and everything else worked when I left.

I have never experienced hard starting in very cold weather even at 10 above zero.

Good luck

Telcoman

 

The hydrometer is a good idea, but these are sealed batteries, can't check each cell.

Even if the alternator is doing it's job and the battery is good, with all the electronics these cars are hard on batteries, is that not true? With the keyless entry sensors, etc, there is essentially a constant battery drain, albeit small, right? That is why Infiniti says it is normal for the car not to start if left sitting too long, if I'm not mistaken.

 

I just put a Red top in mine this week.

 

I have had my 2010 G37 since March 2010, so the battery is over 4-1/2 years old. This battery is not maintenance free which took me by surprise, since the last few cars I had came with a maintenance free battery.
I do my own periodic maintenance, as far as oil, filters and tire rotation.
When I finally realized that the battery had to be checked it was fairly dry. I added almost 2 full measuring cups of distilled water and figured the battery wouldn't last long, because of my neglect.
That was about 2 years ago and the battery still works great.
It would be nice if they could come up with a method of displaying the approximate battery life that is left on one of the info screens.
I will probably change to a new battery when the car gets 5 years old just to be on the safe side.
Tom