Battery Low on Voltage

OLETIMER · 12-31-2004, 03:02 PM

Drove 40 miles south this morning had brunch and drove 40 miles north this afternoon. First part of journery on US 1 and return on I 95. On exiting I 95 my detectror srtarted to show low voltage and than back to highway mode when I stopped at the first traffic signal . This continued till I drove in garage. I shut engine off turned on headlights (zenon) and engine would not start. Usually clicking noises etc. There was about 11.7 volts in battery. At no time diid idiot light show low voltage. It appears my car would have run until battery was too low to operate the various sundry little men that keep the 330ci operating. Why do these things happen at the start of a long week end? Dealer opens hiis door Monday morning at 7:30. I am a one car family. I have it on trickle charge so I can get to the deaker on Monday. Any ideas out there? Under warranty thank heaven. My diagnosis is dead alternator.

OLETIMER · 01-01-2005, 09:43 AM

I left my Battery Tender plus hooked up for 30 hours and battery volts read 12.8. Drove 8 miles with one stop and battery now reads 12.1. Alternator is charging 14 volts, so it appears battery is not accepting a charge. Will take the car in Monday morning at 8 AM and let the dealer sort out the problem. Why do these things happen over a busy week end?

OLETIMER · 01-03-2005, 04:34 PM

Never mind all the help. Dealer installed new battery to-day. What's most important re: this post is that no low battery light illuminated in instrument cluster when battery was too low to start the engine..

RANDY P · RANDY P's Garage

Yep, the light's supposed to go on only if the alternator isn't supplying any current during the car's operation. If you're battery is cooked but the alternator is OK the light will stay off - it's there to tell you only your alternator is dead.

OLETIMER · 01-05-2005, 08:40 AM

Thanks Randy in Seattle. Sequel to this is: next day battery light illuminated. Took it back to dealer who than installed new I hope
alternator. Could have been regulator but as they are in one package the drill is to install entire unit. Hopefully this will end the saga. We go out of warranty 2nd of April so any new part is welcome. First trouble I have had with the ci.. Has been a great car.

RANDY P · RANDY P's Garage

and took the alternator with it. when the cells become unstable that's what you get..Replacing the alternator will be the end of the issues.

Good luck.