Battery Drain Problem

[CePa318IS]

Hey Everyone,

I am having a problem with my 91 318IS.  It has 140,000 miles on it.  It was sitting for about a week due to some crap weather we have been having here.  I went out to start it up to take it out for drive and no turn over.  The lights came on in the car and I could turn the headlight on.  I was disappointed.  I figured I may have left some on and the battery drained.  I checked everything and nothing was left on.  I attempted to jump the car.  When I connected the positive cable to my terminal, massive sparks came.  I was not sure why it would spark so bad.  I thought maybe the battery was already charged and maybe something else was wrong.  I decided to take out my battery and hook it up to my trickle charger to rule out the battery.  After it charged, I hooked it back up to the car and tightened up the cables to the terminals.  There was no corrosion or buildup on my battery terminals.  I turned the key and the car magically started.  I figured the battery might be going out.  I went out for an hour drive with no issues.  I came back and stayed in for the night.  The next day I went out to start up the car and absolutely no response from the car.  No lights, no turn, no sputter, no nothing.  I took the battery back out and hooked it up to the trickle charger.  I put it back in the car and it starts up.  I am sure the battery is dying, I would just like to get some input from everyone on "OTHER" things I should check for that may be causing the battery to drain in such a quick way.

Thanks,
Scott

[RED IS 91]

I found the following with a google search.
good luck

I would check the current draw on the battery when the car is off. It should be next to nothing. Use a multimeter, switch it to amps and put it in line with the battery.

You would do this by taking off the red, or hot, battery cable and putting the multimeter between the battery terminal you removed it from and the battery cable. MAKE SURE YOU ARE ON AMPS. mA. Else you'll blow your multimeter.

You should see a draw of less than .0005 A (.5mA), or around that. It's going to be pretty low.

Look on your battery, you might see something like 8aH, which is how many amps per hour the battery can sustain. For instance, 8/24 = 0.33 amps per hour. So in 24 hours your battery will be dead. A car with an alarm and LCD clock can probably sit for 9 months and start right up if the battery was good when it was left there. That's about .0001 amp draw.

So basically, if you have any noticable draw on your battery then you have a short somewhere. Most multimeters can handle up to 10 amps. Your starter uses about 250-300 amps on a nice day, and 600+ on a cold day. So if you do everything right, you'll either find a draw of about .3 or .4 on your battery, which means it would die overnight. I doubt it would be over .10 because it would die before you got off work. If it's over that, it will blow the fuse in your multimeter. You can pick up a multimeter if you don't have one for about $35-40.

If you have a draw on your battery you can start removing fuses until you see the draw disappear telling you that's the circuit where the short is .

[Cobra Jet]

Does the car have an active alarm system?  Sometimes if the vehicle's alarm system is left in "armed" mode and not started for quite some time, the alarm system can draw on a battery - even though it's a parasitic draw it can wear down a battery in due time, especially if A) the battery is aged, B) if the car is out in the cold (constant temps @ or below 45*) and C) if the car has not been used or started at a normal interval.  If you have other aftermarket accessories in the vehicle, check those items for battery draw as well.

How old is the battery?

[CePa318IS]

Hey all.

Thanks for the input.  The battery is dead.  I found out the battery is 9 years old (March 1999).  I did not have a multimeter to check the draw as described in reply #1 so I just decided to take the battery to a local buddies shop to test it.  The battery is not holding any charge what-so-ever now.  I went out and bought a brand new battery, a Die Hard International.  Everything is working great since the install on Saturday afternoon.  I have not had one drain since the install of the new battery.  Idle is stable and there is no dimming when using electrical devices (A/C, Heat, Radio, Lights).  

Thanks for everyone's help.
Scott

[RED IS 91]

Well,that was easy ....................

[CePa318IS]

Yea the easy ones are nice especially if you do not have much time to work on the problem.  I actually like really difficult problems.  It makes my brain work extra hard.  Plus, when I figure it out, I get that sense of, "Man I am the SHIT!"