Hey all,

Went to start up my C4 after about 3 weeks and discovered a dead battery. The battery's only a year old-- I probably did something silly like left an accessory on (interior light, didn't shut the door all the way, etc.).

I have a battery booster that allows you to start up a car, however, when I attach it up, I hear a clicking sound inside the car around the glove compartment area. After a couple of minutes, my non-factory radio seems to want to turn on, however, it's not getting enough power, so that I could just turn it off. The car won't start at all.. (just dead).. Seems like its power is being drawn from the battery by different things, except they're not "powering on enough" to be shut them off.

What's the best way to handle this situtation?

I imagine the next thing I'll have to figure out is how to unhook that aftermarket alarm system (installed years before I purchased the car). I wonder if that's causing the issues.

UPDATE: I took my other car, attached some jumper cables between it and the Vette and the same things happening. Click sound inside car, behind glove compartment but no accessories will function (can't turn on interior lights, or work power windows, etc.).


[Modified by ChandlerL, 8:05 PM 2/6/2004]

 

:cheers: Before passing judgement, let me ask a few questions :D

1) car was fine before you shut it off three weeks ago? Alt was working, lights, etc. came on? Particularly concerned about Alt performance. Alt's can develop a dead short internally

2) while it's been shut down, did you work on it?

3) battery terminals are clean and tight?

4) battery is only 1 year old?

Preliminary, would almost sound like a dead short in the battery

Answer may lie in the questions above :D

:seeya

:steering:

 

:iagree:

 

You cannot start a car with a dead battery with jumper cables from another car nor can you start it with a battery charger with, "starter boost". Battery jumps are only to help with the 100+ amps a starter motor requires. You should charge your battery for 15 minutes or more before you attempt to start it with a jump. The clicking you hear is a relay that isn't getting enough voltage to stay closed. Starting from dead, the battery voltage slowly rises when charging and until it finally gets to 12.0 volts (considered discharged at this voltage), your car won't work properly. You probably have something drawing excessive off current if your battery is discharged in 3 weeks. Even so, it is not a good idea to let your car sit for this amount of time without periodically charging the battery. Lead acid batteries self discharge about 1% each day and faster with any amount of leakage current. GM says leakage current should be not more than 50 ma. (milliamps). My 87 vette measures 27 ma. If you store your car, either charge the battery once a week, use a battery tender (automatic battery charger), or if you already have a battery charger, buy an interval timer and have it charge your battery once a day on its minimum interval (usually 15 minutes). Lead acid batteries do not like sitting doing nothing and upon discharging, the plates collect lead sulphate which is a good insulator and sitting long enough, the battery will not take a charge and will have to be replaced.
Driving your car for 1/2 hour or so after you finally get it started will not charge it very much. NEVER use your alternator to charge up a dead battery as it will heat the alternator and shorten its life. Alternators are designed to supply current to the cars electrical system and keep the battery charged after it cranks the engine. Leave your battery charger on your car for several 24 hour periods to fully charge it up!
Several CFers found aftermarket alarms drawing enough current to discharge their batteries. You can measure the leakage current by placing an ammeter (VOM test meter set on amps) in series between a battery cable and its battery post (neg terminal is safest). Wait until the courtesy lights time out and then switch the ammeter to lower full scale current so you can measure the leakage current. If leakage current is excessive, you can pull fuses one at a time and watch the leakage current. If it drops dramatically with one fuse, then you need to look at that circuit for the cause of the current.

 

> Before passing judgement, let me ask a few questions

You bet! :)

1) car was fine before you shut it off three weeks ago? Alt was working, lights, etc. came on? Particularly concerned about Alt performance. Alt's can develop a dead short internally

Sure was. Everything was working fine.

2) while it's been shut down, did you work on it?

Nope.

3) battery terminals are clean and tight?

Yep!

4) battery is only 1 year old?

Yep!

> Preliminary, would almost sound like a dead short in the battery

Hmm. I'm trying to get access to a battery charger. Figured I'd take the battery out of the vehicle and charge it for 24 hours. Then put it back in. D'yall think this is the best course of action? I'm concerned that if I do have an accessory that is drawing too much, then simply attaching a battery charger to the batter while it's in the vehicle may not charge it quick enough while the culprits are drawing too much electric.


[Modified by ChandlerL, 11:48 PM 2/6/2004]

 

It is easier to charge the battery in place! You can disconnect one battery cable, the negative cable, and charge the battery. After the battery is charged overnight, you can measure the leakage current and see if it is excessive. Usually even excessive leakage current isn't high enough to affect charging the battery with the cables connected unless you use a trickle charger (1 amp or less) and trickle chargers are used to keep a battery up, not to charge a dead battery up!

 

I would charge the battery and try to start the car. Once you get it to start, see what your voltmeter in the dash reads. If it stays above 13volts with the engine running, your good. See how it does the next few days.

I had the same problem before, when I returned to my Vette after it was stored for a few month. I accidentally left the battery connected. I was able to jump start it with another car. The following few days, it would be dead again in the morning. I installed a new battery and that fixed it for good.

 

Roger, that.

I currently have the battery out of the car and am charging it with a 6amp/12v charger (would rather have one of those newer 12amp automatics but no ca$h).

After 8 hours or so of charging, I'll report back with an update.

JFB: Thanks for the thorough advice. I had to take the battery out of the car, because I don't have covered parking and didn't want to run anything electrical outside (It's been raining here in Long Island for a couple of days). You're absoutely right about leaving the battery in-- it would have been much easier..

:rant: mmfg..gmmmfg.. rocker panel..



[Modified by ChandlerL, 2:16 PM 2/7/2004]