what causes batterey drainage on a car?

Answer 1

on-board engine computers, analog and digital clocks, radio memory, faulty/corroded connections on the battery, and any lights left on no matter how small. and just overall time that the battery has been left without a charging source. just because you don't see a digital display lit up doesn't mean it isn't using power for memory settings.

Answer 2

You need good tight battery connections with no corrusion - both ends of both battery cables - ground and starter. Your alternator needs to keep feeding the battery. There is an easy way to check if an alternator is working properly. With the car running and the hood up, place the end of a screwdriver at the middle of the alternator pulley. Place it at a 90 degree angle. Lay it flat on the center of the pulley. A good alternator will suck the screwdriver against the pulley. It doesn't suck real hard, but there is enough magnetism/ electricity to hold it there. With a bad alternator, the screwdriver will bounce around slightly on the center of the pulley. It's not a real big difference, but you should be able to tell after a couple of tries.

Answer 3

battery drainage is caused by anything electical that is on, computers, radios, clocks, radar detectors, lights, etc...
i dont know if you were simply askinga question or you have a problem but heres a little more info. use a meter and check the battery voltage witht the car off, you should get 12.0-12.6v now turn the car on, if the voltage drops below 10.0 while cranking the battery may need replacement. after the car starts up you should get 13.0-14.5v if so you have a good alternator. slight variences are ok.

Answer 4

I used to have a car that didn't have a very good connection between the battery and the alternator. When the connection went out, the car would run off the battery, but the alternator wouldn't recharge it. This could be your problem.

Also, sometimes batteries just don't work as well when they get old.

Answer 5

what they all said is true but, all these items are not run by the battery its self... the alternator produces the amperage to run them. the battery is mostly used on intial start up, if you over crank your car starter the battery will drain prematurely. a main reason why the battery drains is that the batter produces hydrogen so in time the acid will not activate and the gas will take over the battery causing your battery to run out. i would check your battery for the replacment warrenty or if it's new how long it is so you can take it in.

Answer 6

Not much info. here like what exactly is happening ?? If your battery is going dead like after a few hours or overnight and you know your alternator is working correctly. Try chatging the battery by running the engine and when it is charged disconnect either battery terninal and let it sit for several hours then reconnect and if it has discharged you have a bad battery. Replace it.

Answer 7

Batteries work on energy released by ions in the solution betwen plates in the battery. Those ions create a chemical gradient (reaction) and will continue until the cells inside the battery no longer can provide juice (chemical energy) to supply power to your car's electrical needs.

Answer 8

could be a lot of things maybe alternator or a wire shorting out when the car is running unhook the positive battery cable from the battery if the car quits it is most likely your alternator

Answer 9

another possibility is an under hood,trunk or glove box light that are not shutting off when the hood,deck lid,or glove box door are closed

could be that one of those switches have gone bad,or need adjusting

Answer 10

several things.
A short circuit
A faulty fuse
obviously leaving your lights on
over jump starting a battery, they can only be charged so many times.