Battery Drain

[Gary Kong]

2005 ST. I have an Optima battery, less than two years old, installed and it usually works fine. Last week after two days of not being started, I went to use the ST and it wouldn't start. It had this strange, rapid clicking sound (sounded like it was from behind the dash) and the gauge needles were shaking or vibrating. I did a charge and it was fine. After driving a bit, it was continued to start without incident.



This morning after 4 days of inactivity, it started fine but just before the engine "caught" there was that strange clicking and the needle vibration. The clicking is not the typical sound of the solenoid clicking, I THINK it is an electric sound from behind the dash ... but I could be way wrong about this.



Things about the car: It has a Scan gauge hooked into the data port, it has had an XCAL "performance" tune programmed into it, it has an Optima battery, and it has PIAA foglights connected directly to the batteries second connections (the side mounts, professionally installed).



I'm suspecting that when I do short trips (less than 2 miles) around town with the OEM fogs and the aftermarket PIAA fogs on that maybe I am drawing juice without enough driving to recharge the battery, but I am not sure. My concern is that I can't predict when the ST will decide not to start again, there seems to be no warning. I am willing to remove the Scan Gauge if this may be the cause of the battery drain.



Any help or suggestions appreciated.

 

[scott degroot]

You need to get a voltmeter with an amperage setting on it and connect it between teh negative battery post and the negative battery terminal. This tells you how much current the system is drawing. After 45 minutes the system will go to sleep and then you read what is on the meter. Anything less than .050 milliamps is good, anything over that and you have a dead battery in a day or so. If you are drawing more than .050 then you need to start pulling fuses until ou find the draw.

 

[Richard L]

As l1tech said...or you simply have a bad battery. Yes, even Optima batteries go bad. I have brand new batteries go bad in less than 8 months, and brand name has nothing to do with it.



Since you don't drive it everyday, a simple way to check is to disconnect the battery terminals on a fully charged battery for 3-4 days. After the 3-4 day,s reconnect the battery and see if it starts. If it will not start or cranks slowly, you have a bad battery that is not holding a charge....You don't even need a meter for that :grin:



....Rich

 

[RedRanger 7]

Bit of corrosion on terminals, or maybe a little bit of tightening :driving: .

 

[Alan Peters]

I1tech steps are spot on. You can trouble shoot the drain easily.