Lesson Learned: Battery Light

[jaypete1]

Well, it's not like the last time my alternator went on my car. That was a '91 Chevy, and was able to drive for a while to get to the shop on battery power alone. When my light came on last week, all the electronics on the X5 drained the battery so fast I barely made it to the shop. Less than 15 minutes running time, and my battery is only ~2 years old.

[youry]

the way I check the battery and alternator.
start the car. disconnect the battery! if the car keeps running with the battery disconnected then is the battery (it means that the alternator feeds all the electronics and is in good working worder). if you disconnect the battery and car car stops running, then is the alternator.

[CharlieHustleX5]

Usually, when the battery light comes on it means the battery is not being charged. In other words, the alternator is probably the cause of the problems. As a result, the battery will be supplying power to all vehicle electronics until it discharges.

I had the red battery light illuminate on my 2004 X5 with 61k on the odometer. Turned out to be the voltage regulator was faulty. I recharged my factory battery, replaced my alternator, belts, and associated pullies, problem solved and I did some preventative maintenance as well.