Interstate battery from Costco. Z uses an ordinary battery you can find at most places cheap. If you are looking for batteries for the BMW's and the like, then it is harder to find and cost quite a bit more.

IMO, even $130 isn't that much considering that it will last 4 to 5 years. Most good batteries have 3 years free replacement warranty.

Nissan let me down !
 

I saw that charger on the internet. The guy was cranking a motorcycle many times and after would go to a truck and start it and go back to the motorcycle again and crank it up several times and that thing still had power, wow. Amazing tool and compact too.
I bought a SOLAR battery tester and my CCA was 400 but not enough to get a new battery because Nissan said it was border line acceptable. This is so much B.S. from Nissan. They can't replace a stupid $100.00 battery after I spent all this money on a brand new fully loaded Z.