BMW Alsway has an excuse

[Penguin]

Originally Posted by nra4.8is

One if you had a parasitic draw and the control unit wasn't working properly you wouldn't be able to even start the car. The control unit is designed to cut consumers even while sleeping to ensure start capability. Have you ever been able to not start? Have u ever had to reset the clock? What year is the car? Five year is rule of thumb for routine batt replacement to ensure a stable electrical system.

Two times in the past month it has failed to start when the vehicle was in single digit temperatures. One time it cranked about 1 second, and that was the end. The second time it wouldn't even crank. The morning I took it to the dealer, it cranks a half second and stopped. Tried again, cranked very slowly for 1 second and started. In each case, it was placed onto a CTEK 7002 smart battery charger afterwards and would start normally after overnight charging (obviously did not put it on the charger the last "slow start," as it was the trip to the dealer).

Never had to reset the clock.

Vehicle is a 2010 that is 3 1/2 years old.

Never had a problem until last Fall, when I started getting frequent "excessive discharge messages." Took to dealer in November for oil change and said I was concerned about the frequent recent "excessive discharge" messages that I had not gotten in the prior three years of use. I expected the dealer would have at least done a load test on the battery. What did the tech do? Wrote on the service record "no codes found."

Apparently the BMW power management computer doesn't log "Excessive discharge messages."

P.S. I sometimes log data via the OBD-II port using a CarChip, which is later downloaded to my computer. System voltage is typically just below 15 volts for the minute of two after starting, and then it settles-in to a range between 14.6 v and 14.9 v.