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Battery light

Discuss problems you have had or are having with your Z4
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A1wil
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Battery light

Post by A1wil » Sat Jan 18, 2020 3:22 pm

Hi guys, so I took my car out today for the first time in two weeks because of the bad weather. After about 15 mins of driving the battery light came on. About 5 mins later all the lights came on and the car died. I managed to get it started with jump leads but the light came straight on as soon as I took the leads off. Rather than just go straight in and put a new alternator has anyone else had any issues. About a month ago I checked the battery voltage 12.8v when it was not running and then 13.9v when the engine was running so it was working . Anything worth checking ??? , I'm thinking of checking the voltage directly from the Alternator anybody done this. ??

Cheers guys

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kis
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Battery light

Post by kis » Sat Jan 18, 2020 3:32 pm

Battery could be shot? Have you had it tested?
(I have one and it tells you how many cca it has compared to spec). It also tells you if it needs a re-charge or if it is too fudged and needs to be replaced.
My E85 Z4 3.0i SMG

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buzyg
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Battery light

Post by buzyg » Sat Jan 18, 2020 5:26 pm

A1wil wrote: Sat Jan 18, 2020 3:22 pm Hi guys, so I took my car out today for the first time in two weeks because of the bad weather. After about 15 mins of driving the battery light came on. About 5 mins later all the lights came on and the car died. I managed to get it started with jump leads but the light came straight on as soon as I took the leads off. Rather than just go straight in and put a new alternator has anyone else had any issues. About a month ago I checked the battery voltage 12.8v when it was not running and then 13.9v when the engine was running so it was working . Anything worth checking ??? , I'm thinking of checking the voltage directly from the Alternator anybody done this. ??

Cheers guys
The battery started the car OK. Then it discharged whilst running. Has to be alternator related. Check leads & belts too.
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A1wil
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Location: salisbury

Battery light

Post by A1wil » Sat Jan 18, 2020 5:47 pm

Well I have pulled the positive lead of the alternator and there is 0.46v so I'm going to go with the alternator. Seen one on eBay £100 " 333374883932 " . Do I need to remove the radiator fan ? .

mr nurburgring
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Battery light

Post by mr nurburgring » Mon Jan 20, 2020 7:49 pm

Your battery could be showing 12v but there may be a couple of cells down causing half cold crank amps or worse, halfords do a free battery check, I would run it down and get them to test it before you put an alternator on.

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