Just getting a click when I turn the key

battery voltage in DIC reads 11.7 volts - drops to 11.4 when headlights switched on. temperature is 55 degrees - Florida!

No codes

What voltage would a good battery show?

Cheers, Andy

PS I guess the answer is in Bill's electrical post but it has now reached 59 pages!!

 

Whatever you do, don't read it....you might learn something....

Seriously.....go to post #590 in Bill's electrical thread.

 

Many thanks - how did you know it was #590?

 

Lucky guess.

That will help you if you think something is draining your battery.

 

A lucky guess! I hoped there was a secret

Actually, I don't believe I have a drain. I think the battery may have failed in one cell.

found a battery website - a good battery should read 12.6 volts, apparently.

 

I get it. "Lucky" guess. Good one.

 

Yup - battery failed - jump started perfectly this morning.

Charging voltage is over 14 volts, so alternator OK.

Seems like a battery can just fail overnight.

Correct AC Delco fitted in March 2010

 

Dealer confirmed battery failed and replaced it free of charge.

Thank you Bob Taylor Chevrolet Naples FL

It has been said that a hot climate kills a battery quicker than a cold climate - I didn't know that.

 

Glad you got a new one on warranty. A hot climate can kill a battery just as easily as cold but it would be good to check why the battery failed in the first place. Often, faults with the Vette are the car not the battery. This post I made might help you make sure you don't have an underlying problem.

Identifying Battery Problems

The C5 eats batteries unless you take some regular precautions. If your battery continually dies its either the battery which is on its last legs or something on the car.

You also need to look at how you use the car. Is it a daily driver? If so the battery should be getting a good top up every day so you may have a problem.


Is it a DD but you do short trips? If so you'll be taking a lot out of the battery every time you start. For a short trip, say less than about 20 mins, you won’t top it off properly. Eventually it'll drain.

Is it a weekend car. If so, this takes a lot out of your battery. There’s a 20MA drain even dormant. If you don’t drive the car for a reasonable time every week or so, it'll kill the battery. In this case you really do need a battery tender.

You’ll know when your battery is bad. As it gets low you may get strange electrical indications (random warnings and U fault codes). As it gets lower it may drop the memory settings or defaults such as HUD settings. Eventually you’ll get the dreaded chattering relays in the footwell and eventually the lights on the IPC will disappear.

Most batteries can be recharged quite successfully, although AGMs are harder. Start by checking the charge on the battery. Don’t read the DIC when the car is off. The value you see on the DIC is alternator output when the car is running. It will always measure an inaccurately low voltage on the battery when the ignition is off and figures of 11.0V to 11.9V is normal in this case. With the engine on, the voltmeter should show between 13V and 14.5V. You need to measure voltage across the battery terminals using a digital multi meter if possible. A fully charged battery measures 12.7V and a fully discharged battery measures 11.9V. Partially discharged batteries will give a reading somewhere in between.

If the battery is low give it an overnight charge (or put it on a battery tender until you get a fully charged indication) and retest it. A true test is under load and Autozone will do that test for free.
If you have an AGM battery like the Red Top and it has been deeply discharged it's harder to recover it. This might help:
http://www.youtube.com/watch?v=dIoaL3DWWEg

If you’ve recharged it and it still runs down, then you need to start looking for excessive drains. Bill Curlee posted a good method for checking:

http://forums.corvetteforum.com/1567522286-post590.html

There are some common faults which are well known for causing problems:

First to check is the interior lighting rotary switch on the drivers panel. It’s possible for that to be turned on as there’s a setting (fully clockwise) which bypasses the auto off function. Turn it fully counter clockwise and check after about 30 minutes (preferably in the dark) that the interior lights have gone off.

If it’s not the lights, something has failed or is badly installed.

Have you fitted an after-market device which draws current? Typically it’s a cellphone charger, radar warner or a similar device that’s the problem.

If still no joy, you need to start pulling fuses to identify the problem.

The power seat switches on the side of both seats are notoriously unreliable. The switch becomes sticky with use and can stick in the “on” position. You shouldn’t damage the motors as they are thermally protected. The fuse may blow so worth checking (Fuse 36 20A in footwell).

The driver’s lumbar motor can also cause issues so check this too (mini fuse 3 15A in footwell). The seat controls connect under the seat. Pull the connector and if the drain stops that’s your problem.

Less common but not unheard of are failures of the headlight motor control module the alternator and the Bose Amplifier under the dash on the driver’s side.

 

Thanks for taking the time to post your battery advice - over the weekend I read all the posts in the end, and found out some more stuff from googling.

It's not a charging issue - there was a dud cell when the dealer tested the battery. The car is my DD, albeit for some short trips. But more significantly, I only use it in the winter, as I am in UK in summer. The storage garage doesn't have an electrical outlet and the rules are that the negative lead of the battery must be disconnected. Amazingly, in November, there was sufficient juice to start first time! May not have been good for the battery longevity though.

I'm pretty sure it's not a hidden drain issue, but I'll check it out as you suggest.

Are you a Brit, or a Yank who couldn't be parted from his Vette? I've often wondered when I have read your posts

 

No trouble and I hope you find the problem. You'd think that the battery would survive OK if its disconnected over Winter. Battery life varies in my experience but after 5 years it might just be getting tired. Heat can kill it as much as cold. What type of battery do you have and how old is it?

Bill's advice on how to run a drain check is easy to follow and it'll give you peace of mind that nothing is running it down. I keep mine on a tender if it sits for any length of time. The parasitic drain will kill the best of them after a few weeks/months.

I'm retired Brit military. Had 2 tours of duty in the USA. Tried to buy a C4 in TX but had to make do with a Camaro which my son now owns. Bought the Vette when I was posted to Vegas and brought it home when I returned to UK. I guess I'm a Brit who couldn't be parted from his Vette Why the Oxford connection?