Possible Alternator problem ?

Wasa · 05-03-2025, 07:27 PM

Hi guys , recently my e60 525i is having trouble to stay on after 10mins as I can start and drive . I’m thinking it might be time to replace alternator? Any thought ?

Thanks

Ralph III · 05-04-2025, 10:34 PM

Hello OP,
Put a multi-meter on the battery leads and check the voltage. It should be around 12v or so. Now turn the car on and check the voltage again. It should be somewhere around 13.5 volts or higher. If it is, then your alternator is charging the battery correctly. If it is charging at a rate lower than 13v, then you probably have a failing alternator.

Good luck,
Ralph

n000000000b1 · 05-10-2025, 06:14 AM

Agree, check your alternator output voltage. Even better, if you can scan the car with ISTA or protool, you'll probably get a good hint at what's going on. How old is your battery? ISTA can also tell us your battery state of health.

aade · 07-17-2025, 02:18 AM

What exactly happens with your car after 10 min? Does it start back up after it’s stalled? If so, perhaps the alternator isn’t your problem.

How does it idle?

05-03-2025, 07:27 PM	#1
Wasa Second Lieutenant 31 Rep 228 Posts Drives: E46 M3 E60 M5 F82 M4 F85 X5M Join Date: Aug 2018 Location: Canada iTrader: (4)	Possible Alternator problem ? Hi guys , recently my e60 525i is having trouble to stay on after 10mins as I can start and drive . I’m thinking it might be time to replace alternator? Any thought ? Thanks
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05-04-2025, 10:34 PM	#2
Ralph III Private First Class 144 Rep 135 Posts Drives: 2018 BMW 650i Gran Coupe Join Date: Apr 2023 Location: Alabama iTrader: (0)	Hello OP, Put a multi-meter on the battery leads and check the voltage. It should be around 12v or so. Now turn the car on and check the voltage again. It should be somewhere around 13.5 volts or higher. If it is, then your alternator is charging the battery correctly. If it is charging at a rate lower than 13v, then you probably have a failing alternator. Good luck, Ralph
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05-10-2025, 06:14 AM	#3
n000000000b1 Private 18 Rep 55 Posts Drives: E70 X5 35i, F15 50i M Sport Join Date: Jan 2020 Location: Atlanta, GA iTrader: (0)	Agree, check your alternator output voltage. Even better, if you can scan the car with ISTA or protool, you'll probably get a good hint at what's going on. How old is your battery? ISTA can also tell us your battery state of health.
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07-17-2025, 02:18 AM	#4
aade New Member 5 Rep 82 Posts Drives: BMW E61 5er Join Date: Jul 2025 Location: Stockholm iTrader: (0)	What exactly happens with your car after 10 min? Does it start back up after it’s stalled? If so, perhaps the alternator isn’t your problem. How does it idle?
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