Quote:
Originally Posted by RToth
Exactly, but with the drop in voltage overnight with the battery it had in it as well as it being a cheap remanufactured battery and also not even being the correct type for the X5 I replaced it anyway. Alternator will be fixed before I rip into the trans as well and still plan to explore a few other options such as dropping the pan and checking the turbin speed sensor for debris on it indicating the A drum failure. Worst comes to worst I fix the charging system, replace some bushings (I have a hydraulic press) and rebuild the trans and I have an amazingly smooth really nice looking rust free daily driver  |
According to your numbers, it dropped 1.38V overnight. The first reading was taken directly after shutdown.
Dropping 1.38 volts overnight after running all day with a faulty alternator does
not indicate an unhealthy battery.
The battery light should be your first big red flag. If the alternator is not producing adequate voltage or amperage while running, you're going to have a lot of issues, regardless of the condition of the battery.
When the engine is running, the battery does very little. After startup, it's basically there to absorb voltage spikes and to take a charge. The vehicle is getting nothing from the battery until the alternator starts to die, like yours is. Replace the alternator and get back to us.