Purchased a new 2019 K900 in December. The battery slowly drains and dealer and Tech-Line can not find the problem. Drive the car an average of 20 miles per day. I can tell when the battery is below 70% charge because the start/stop system and the coasting options stop working.
Once the dealer charges the battery, both systems start working again.
Dealer has checked for parasitic draw, charging system, and battery. All OK.
Just curious if any others have experienced this problem.

I believe Bob Johnston also had this problem. Not sure if he ever got it fixed. Take a look around post #135 in this thread: https://www.k900forum.com/forum/new-...9/index14.html

So just experienced a strange issue. The car has been parked in the garage since Tuesday (3 days) and my wife went to start it this morning and it had trouble starting (slow to start). When it started it was running a bit rough. She called me out into the garage and told me it flashed a message on the cluster "Battery discharge due to external devices". Now the only thing plugged in to the car was just the Belkin USB cable to the front USB slot adjacent to the wireless charger with no device attached. I wouldn't think that the cable, by itself, would produce any sort of load on the car with or without the ignition or acc on. I know the cable has a small 56k ohm pull up resistor built-in but I'm not aware that the USB would have power while the car's ignition is off. Have either of you experienced this issue?


This is exactly what my car did "battery discharge due to external devices".
After a few days of viewing this and it would immediately go off the screen.
I went to the car one morning and it was completely dead. No dash lights, nothing. Like there wasn't even a battery in the car. I couldn't even pop the trunk lid. Towed the car to the dealer and they finally replaced the fuse block. I thought this did the trick but a couple months later I noticed the start/stop system wouldn't work or coasting would not work. Back to the dealer and found the battery level below 70% charge. The software will not allow start/stop below this charge level. After charging the battery back up, everything works fine. Dealer can't figure it out. Car has been back for numerous testing but still no solution. I drive about 20 miles per day.
They are saying that may not be enough to keep the battery properly charged. I don't agree with this. Any input from others with the new 2019 k900 would be appreciated.