Battery Drain
Thread Starter
Drifting
Joined: Sep 2005
Posts: 1,867
Likes: 3
From: Pasadena Maryland
Battery Drain
Yesterday my 93 would not start, dead battery. The battery is a 2.5 year old Interstate. After I charged it the car started OK. The volt Gage showed 12.5 after charging, if I turn on the lights (engine off) the battery voltage goes down to 12.0 and stays there after I turned them off. I checked the drain on the battery and measured .016 Amps (hood light fuse pulled, doors shut, no lights on). That does not seem excessive to me. The car is a garage queen that only gets driven once or twice a month. Should I expect to replace the battery ever 2 or 3 years, or am I missing something here? When driving the voltage gage shows 14.3 or 14.5 normally.
Intermediate
Joined: Sep 2006
Posts: 34
Likes: 0
From: Broomfield Colorado
You should check specific gravity, that will tell you if the battery has a bad cell. Otherwise it sounds like you have done all the right things to verify there isnt a drain. If you let it sit that much that can cause a battery to sulfate and will shorten its life. Boats are the same way in that they sit a lot and batteries don't last long.
One way to try to cure sulfation is to put a big load on the battery (headlights) and drain it down to below 10V. Then charge it back up rapidly. Do this 4-5 times and see if the battery starts lasting longer.
One way to try to cure sulfation is to put a big load on the battery (headlights) and drain it down to below 10V. Then charge it back up rapidly. Do this 4-5 times and see if the battery starts lasting longer.
Thread Starter
Drifting
Joined: Sep 2005
Posts: 1,867
Likes: 3
From: Pasadena Maryland
I went to battery warehouse last night to have my battery tested. As soon as he put a load on it it went down to 10 volts. My CHEAP battery tester (Metal box with a resistor wire) showed that battery as being good for a 600 amp hour battery. I did not get any warning that the battery was getting bad, no slow cranking at all. The car was charging at 14.5 volts with the old battery, now it charges at 13.8 with a new one. Maybe watching the charging voltage is the clue?
