91 passat gl
 

Having issues with my battery, not that great with cars so any help would be awesome before i take it in to a friend whos a mechanic.

Battery is cutting out on me, previous owner put a igniton button so you dont actually start the car with the key but a ignition button. Have run the car for hours works fine but within days battery dies. Charged it back up but keeps dyin on me. Im thinking that the cable connecting to the battery keeps draining it but i am not certain.

Any help would be appreciated if ya need additional info lemme know.

After market stereo? If they didn't use the proper constant, I usually use the cigarette lighter one, but who knows what they've done, if it has a start button. Start with the stereo, good luck from there.