I was driving home from work, had the auto wipers, fan and radio on. I was almost home and I got a random electrical fault on I-drive. Said stop driving immediately, bring in for service etc. It was on for a couple seconds then turned off before I could even finish reading it.
I pulled over. Checked the fault list under service on I-drive and it said all systems ok. I turned the car off then back on and checked the faults again. Still says all systems ok.
I've never had this problem before. Is this a sign of either the battery or alternator going?

 

Did you hit a bump or ran over anything? You should get battery checked just in case. Also, make sure the cables are tight, don't over tighten the bolts will break.

 

Didn't hit any bump or anything. I'll check the battery cables.

 

What year is the car and how old is the battery? The OEM battery is stamped on top of the negative terminal with the week number on top and year on the bottom.

 

Sorry its an 04 545i and the battery is a couple years old. Non-BMW battery.

 

Just checked the battery with a DVOM. 12.3V with engine off and 14.2V - 14.5V engine running. Also the cables are tight.

 

While this might spark some nay-sayers, however I have to ask this question...Was the battery registered when you changed it? Does it have the same spec as the original? I've seen threads of weird electrical issues a year or 2 after changing a battery without registering.

 

Don't know if it was registered or not. I bought the car with this battery in it.

 

Can the battery be registered now? Or only when you replace it?

 

Can be registered anytime, however you can see via Diagnostic when and if yes - the battery was registered. Also check the type of battery - I heard about problems with gel battery. If you have it, something additional must be done via diagnostic.