You can buy a lead-acid battery, similar to the OEM that came with your new Infiniti or one of the newer engineered batteries called a "gel" or an AGM (absorbent glass mat battery).
The Optima Red Top, an AGM, (I installed an SC34R model) offers a truly maintenance free battery. Because of its design, the lead is pure; it's rolled so it doesn't need the added strength to support itself as a conventional battery does. Vibrations are better handled by the AGM design. The Optima Red Top 34R is designed as a motor starting battery. It cranks out CCA (BCI 0-degrees F) of 800 amps or MCA (BCI 32-degrees F) 1000 amps. The OEM cranks out about 440 amps.
More power, much longer life (free replacement for 3-years) and totally free maintenance free battery were the major reasons I spent about $165.00. I did send in a manufacturers coupon for a $25.00 rebate. That will lower my cost to $140.00.
CliffordS

 

I did the same thing when I replaced my battery. I know you've already found some plugs that fit well enough, but for future reference you can order these through Riverside Infiniti. You could probably get them through your local dealership too. I ordered 10 extras just to have around in case I break one on accident. Once you figure out how to remove them properly, they are very easy.

 

The Optima website lists a Group 35 (8020-164) battery for the Infiniti G35.
The 34R (9003-151) is slightly larger but by fractions of an inch.
Are both batteries an acceptable choice for this car? Is this a case of six of one, half a dozen of another?

 

For our cars, it should be the 34R battery (the letter 'R' designated for reverse battery posts). I got mine at Advance Auto Parts for $155 (with the $10 core charge).

 

Didn't I already say that? You must be from Oklahoma J/K

Hook 'em Horns!!

 

Haha, must have overlooked it. You Texans and your funny jokes!