Battery Light's False Alarm Car Performs, Light Misinforms

The normal reading for a fully charged battery would be more or less 12.6, with the engine off and no lights on. Once the engine is running, ... Many reasons for this, bad battery, bad alternator, etc. I suggest checking the battery voltage, car off, and then hooking the battery up to a 2-10 amp charger ... Thats because when the car is off, the alternator isn't charging. It's supposed to do that when there is no current running from the alternator ... But having the voltage gauge installed really is key to being able to drive in a car like this without worrying each time it comes on. Usually, ... ... car is different like with comparing readings from trucks to econo cars. But the car starts fine, headlights are fine, interior lights dont ... Ok this is going to sound retarded i know but i have had it happen to me in other cars in the past, and I'm really not sure that this will fix ... but everything runs fine electrically when running...as in lights ... hi all , wife went to open car today and noticed the battery light ... One possibility, and usually the most common of course is that the alternator has failed, and you are running on your battery. Yes your car has ... Your engine is off, at this point. When your engine is running and your alternator is charging, the voltage from the charging alternator is felt ... It seems like the only possible sources of this problem are: loose belt (I don't think so), bad ground (seems ok, but maybe not), bad alternator ...