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Old 02-04-2013, 11:49 AM
Tom K. Tom K. is offline
Officially Welcomed to the 'Fest
Location: Maryland
 
Join Date: May 2008
Posts: 2,571
Mein Auto: '07 328iT.'13 Boxster
Quote:
Originally Posted by SilverX3 View Post
Do a voltage check
At rest engine off voltage should be min 12v
At charge engine on should be 14v or about

At rest if your battery less than 11v then it s time to replace battery
At charge if battery about 12v then time to check the alternator
Before replacing battery or alternator, have the IBS checked as it controls the alternator charge. An intermittent IBS fault in my E91 caused a spurious "Low Battery Voltage" warning within one minute of shutting the motor off but leaving the ignition on.

Tom
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