markfisher58

I have a 2000 convertible and for the past year the battery has gone completely dead at least 4 times. I am on my 4th new battery and it now has already lost power. Any ideas what might cause this?

clegg

You either have too small of a battery or there is something causing it to drain. Check out Bill's link. http://forums.corvetteforum.com/1567522286-post590.html

4 KRUSIN

We need a little more info. How long is the car sitting before the battery goes dead? These cars are known for parasitic drain, so if its sitting for 3 or 4 weeks, the battery can drain. If this is the case, invest in a Battery Tender or equivalent and hook it up evry time it is going to sit for a while. Also, if this is the case, if you need a new battery now, invest in a battery that will take a complete drain. I have an Optima Yellow Top and it will take a drain (I know from experience). If this is not the case, you have something more significant drawing it down. Someone that has more technical experience should be able to help you in this case.

markfisher58

Have had a trickle charge on the brand new battery since Nov. and it still went dead.

Mr.Bill

What battery you using and charger do you use?

calvins

wow, assuming it's the right battery for the car, that's some serious drain if a Battery Tender can't keep up. I've used BT pluses on everything from motorcycle batteries to each of my Vettes, to mega deep-cycle batteries and they always keep them charged. On the Vettes I never have disconnected the battery for winter storage (NY state) and never had an issue.

If you aren't techie enough (no offense, I sure wouldn't be) with the electrical system to debug the drain, I'd get it to a Vette shop/guy pronto. Something's sure as chit amiss!

Stupid question though... did you unplug your light in the engine compartment? Those switches are notorious for going bad.

Vetteman Jack

Could be it is just a bad battery or you could have something that is not shutting down properly and really causing a drain on the system. Might want to get the battery tested first, then go from there.

markfisher58

This is the 4th new battery in the past year. My GM dealer recommended the battery. I am fairly confident it is not the battery now.

David Shiel

charging system.

calvins

Doubt seriously if it's the charging system if it's going dead while in storage for a bit with a charger on the battery, something is draining excessively.

RMBLROAR

Don't know if this would do it but check that the lights aren't on in the vanity visor mirrors....

Dave68

You might want to consider an auto electric shop if troubleshooting electrical issues is not your thing. That type of shop tracks down all kinds of electrical issues, every day and often get customers from dealerships that give up.

markfisher58

Anyone know of a good electrical shop or mechanic in the Columbus OH area. Would like to get this resolved before spring.

calvins

Can't help ya with that Mark but did you check the engine compartment light? Honestly, they go south a lot.

markfisher58

there isn't a light in the compartment. do you have to unhook the actual connection?

calvins

Well, if the bulbs out - I don't see what disconnecting the connector (by the right headlight) would do.

Good luck, hope you find someone who can track your leak down. Electrical gremlins can really be PITAs

donald4972

OP, you have an electrical issue, you asked about, with your car.

When 'Mr Bill' gets involved, and asks you "what battery and what charger do you use', you then ignore the rest of us for a while, answer his questions, and listen carefully to any suggestions he might have next, to help you.

That's the best advice I can give you. Hope your problem is solved soon.

Bill Vett

I would start with looking at lighting in the interior,visor mirror vanity lights, glove box. Have you had any issues with warning lights on the dash. Have you checked to see what codes You have? You could have LDCM codes that may be an issue in the drivers door that could drain the battery.

VetteCrazyRichard

Had the same problem. Although the auto parts place said the battery was OK, it wasn't. Finally, took it to a reputable shop and they idenfied the problem: a bad alternator. So, they replaced it and it's been 100% ever since.
Good luck. Use a good shop to diagnose. Not Uncle Charlie, unless he's a pro.

DeeGee

Great info from 8vette7 as usual

I posted this a while ago which may help but I'd start on the likely drains

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:

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.