My 03 Z has the original battery in it. I've been sick for a couple months and couldn't start it up, I did put a charger on it every 2 weeks but never tried to start it. Today I had to start it but all it did was sound like tick/tick/tick like a ticking machine gun. Voltmeter said 11.99 volts so I charged it for 5 hours and it still wouldn't start. Voltmeter said 12.15V and it dropped to 12.05 V in an hour. It has been >100 deg. here in Ga.for most of the month of Aug. How many Volts does a good battery usually hold and how many volts do you need to start? Looks like I should just get a battery right? Do the front battery terminals come off with a 8mm wrench? And does the front hold down screw on the battery tray need a 10mm wrench? How is the hold down tray held in the back? Never changed out a battery in a Vette is there anything I should know about? Thanks for reading this guys any help or comments would be appreciated. Jerry

 

My meter only reads about 13 V usually, so I would think that 12V should be enough to through the starter over. Maybe that is the problem. Do your lights come on/radio?

 

put a new battery in and you're good to go. its easy. don't remember what size sockets i used but trial and error will tell you which on fits.
just remember to unhook the neg. first and connect it last.

 

You need current to start, voltage reading with no load on the battery is meaningless.
Your battery has crapped out.
you can take it to the auto parts store, they should be able to test it under load.
Batteries usually just fail with no warning

 

A fully charged battery will read about 13.6v.

With the motor running you should have about 14.4v (alternator working).

Less then 12v is not a good indicator.

 

Yes the terminals are 8mm (or 5/16). The tie down is probably 10mm, but I don't remember. There is nothing else holding it in. Just the one bolt. I also agree that you should remove the negative side (black) first.

 

I want to thank you 5 guys for taking the time and offering your advice. It should be EZ now, looks no different then any other battery.I'm thinking Duralast/ heard Optimas are not that good.