2nd time battery dying

[cnovak861]

04 745i...
108,000
car was running fine,all of a sudden,
every light on dash comes on,and
battery is dead...2nd time,1st time was
in the winter,about 3months ago,went
got a new battery,and now it's doing it
again...any ideas on what's going on
PS...the tilt light comes on too
same with the transmission light...

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[White94RX]

Was the battery registered properly? Have you read any and all fault codes from every control module in the vehicle? Has the alternator been tested for under/over charging? Have you had the system checked for a battery draw?

There's no way anyone over the internet can properly diagnose your vehicle properly without any and all applicable information. Without the needed information, anything will be just a guess. The car is a rolling computer. It can tell you what's wrong with it.

[Spandrel]

There's something on the cable that's supposed to short everything out in an accident that can go bad. Had all kinds of battery problems that sorted themselves out after replacing the cable - had a shop do it, so I can't give you full details, but perhaps someone else here can point to the specific issue. I recall it was a cable replacement, though

[Qsilver7]

Hmm, any follow up? Was the car being driven since the last replacement battery or does the car sit? And if it is sitting, is it on a battery tender/maintainer...or is the battery being allowed to discharge and sulfate...all which can cause damage and shorten the battery's life.

[jclausen]

Put a new battery in, register it and then do a charging system test, then a parasitic draw test to start. The battery should be a agm battery

[Qsilver7]

04 745i...
108,000
car was running fine,all of a sudden,
every light on dash comes on,and
battery is dead...

Still no follow up?

The description in the quote above is usually what occurs when the alternator gives up the ghost. The battery can only keep things running for a short period all by itself...and as its voltage starts to drop...electrical systems/components start to shut down (its like a boxer being hit with an uppercut...starts to see stars...the room starts to spin...then they face plant into the canvas).

So have you had a chance to have the car diagnosed? Was it the alternator? Or was it a battery issue?