I have a 2000 coupe. I store it inside and start it every other week. This has worked well in the past. Two years ago my battery went flat once, I trickle charged it and all was fine. I went to start it yesterday, nothing... When I put on trickle charger it made weird noises. It wouldn't jump start. I tried a better charger, it kept kicking out. I removed battery and the best I could get was a 60% charge. I installed and nothing, no lights even. Do I just need a new battery? I hope something hasn't happened to computer/wiring. It started fine 2 weeks ago.

Gotta have enough current.It doesnt take much or long to run down a battery in a C5. Disconnect the negative post when she is gonna sit awhile. Once my battery is run down I never trust them. So what is up with yours? Insufficient charge, or the cables are not tight, posts are corroded one of these. Jump start is always risky be careful you can cause big issues.
If you need to run get a new battery with enoung CCA cold crank amps Best of luck

Thanks, I know there's no corrosion. I keep the engine bay spotless! My buddy came over to help out and couldn't believe he was working on a 10 year old car!! I'm guessing the battery has just seen better days... When I pulled the battery out I checked for any fluid/leaks, all is well.

I would go wth the Red Top battery which is jell filled and does not leak. Some of the Delco batteries have leaked from the positive post and the acid ran down on the wiring harness to the computer causing big problems. A battery tender is also a good idea.

If the battery is non-sealed, there is a product that will supposedly de-sulfate the plates and restore the ability to be recharged. I think I have seen it for sale in the JC Whitney catalog, but I can't think of the name of the product. If you were a chemical engineering major, you could probably come up with what you need for a couple of dollars or less.

My experience in batteries is that Caterpillar has a battery with the most CCA rated at a colder temperature than others. Also they have one heck of a warranty: If their battery should take a crap and you can get it back them as late as the LAST day before the warrantee is up you will receive a brand new battery, no charge.
It can't get any more simple than that.

Your battery is gone, it is 10 years old now if original.

Regardless of miles, if it is the original one, it is toast.

Agree! It isnt worth the chance of getting stuck somewhere. Once they need a charge they are on borrowed time two times needing a charge or 4 years and I got no confidence especially in the Corvette that eats voltage even while sleeping. For $125 for a new one it is worth the assurance you will get home every time you take it out.

The first time my C5 battery went dead it gave me the normal warning signs first (strange alarms, DIC and HUD resetting misc features for no reason). The second time it just quit cold turkey and would barely let the car run after jumping it. At least I was at home when it happened.

Would have to agree. 10 years is a long time to get out of most batteries.

I have what the call a "Smart Charger". It has
a mode for wet or jel batteries, it floats at 2 amps like
a battery tender, also tells you the amount of amps
battery currently have. The good part is it has a mode
to de-sulphate your battery but take 24 hours to do so.
Wally World for $75.00
It also has a 75 amp jump start mode,
and tells you it you have a faulty cel. I have had
it show a faulty cel and after 24 hours of de-sulphating
everything was a ok. Oh, did I tell you it also has
mode to ckeck alternator?
Cannon