How do I keep my car battery from draining overnight?

If I detach the car battery terminal cables at night and re-attach them in the morning the car starts fine. But if I leave the battery 'connected' as usual it goes dead overnight. Somehow it's 'draining' when attached. How do I find out what the problem is and how do I fix it?


Thanks!|||Do you have any mechanical and/or electrical ability?


Disconnect the battery cable, and connect a test light between the cable and the battery terminal. The light will come on.


With the doors closed, check for glove box light, trunk light, engine compartment light etc. Make sure the courtesy lights are out. Then begin to remove fuses, one at a time until the light either goes out, or dims considerably. Now you have located the circuit that is the problem. Locate the component or wire or circuit that is the parasitic drain and repair it.





BTW - - Do you have an AMP or does you audio system remain "hot" while the key is off? Some things to check.|||Batteries can be quirky. A good battery will hold overnight even if a low draw light or radio is on. have the battery checked.. Also check if a current draw is happening with a badly adjusted trunk light, interior or hood light Auto electrician should pinpoint with a short inspection.good luck|||well my first question to you is do you have an aftermarket stereo or possibly an amplified speaker system if you do its probably hooked up wrong so that the power is constantly on.. if you dont your car may have an electrical short which could be anywere take it to advanced auto or some other parts store and tell them your battery is dying they will probably test your charging system just start from there..|||I had a similar problem and couldn't figure it out,bought a brand new battery and all. But one day I could hear something humming or running it turned out to be my electric antenna which was broke and would run constantly even though the antenna itself wasn't there. So i just disconected the fuse no more drain. Maybe check for somthing like that,even like and uder hood light or trunk light or dome light is enough to drain the battery!! Good luck.|||I'd suggest you take it to a shop so they can do a draw test on it and determine what is causing the draw.|||Get to a mechanic one you trust and you know wont screw you over just to get paid, explaine the problem and go from there. But for now keep detaching and reattaching as you need to specially since it works. But gets a bit old after a while Im sure. Good luck|||Remove the fuses one at a time and check for current draw. Place an ammeter in place of the fuse and see how high the current draw is. Or if you dont have one, remove one or two fuses overnight and see if the battery still drains. Then you can narrow it down.