How can I check if my BMW 2 Series alternator is charging the battery properly?

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How can I check if my BMW 2 Series alternator is charging the battery properly?

My BMW 2 Series battery keeps dying even after I jump-start it. I suspect the alternator might not be charging the battery properly. How can I test the alternator to confirm if it’s working fine?

Garitips asked on 19 Feb 2025 14:35:45 pm

1 Answer

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Garitips - on 19 Feb 2025 14:44:57 pm

A faulty alternator can prevent the battery from charging, leading to repeated dead battery issues. Here’s how to check if your alternator is working correctly:

Check Battery Voltage with a Multimeter:

Before starting the car, connect a multimeter to the battery terminals. A healthy battery should read 12.6V.
Start the engine and check again. The voltage should rise to around 13.8V – 14.7V. If it stays the same o r s, the alternator is not charging the battery.
Observe Dashboard Battery Light:

If the battery warning light comes on while driving, the alternator may not be supplying enough charge.
Check for Dimming Lights:

If your headlights o r interior lights dim when you use other electrical components, it may indicate an alternator problem.
Listen for Unusual Noises:

A failing alternator can produce whining o r grinding noises.
Solution:
If the alternator is not charging properly, check the alternator belt for looseness o r wear. If the belt is fine, the alternator may need repair o r replacement.