The IR transmitter for the remote locks uses four mercury batteries. (Varta # V625PX) This was a pretty common camera battery a few years ago. Mecury batteries are no longer legally sold in the US, and the replacement 626 batteries are alkaline. The mercury batteries are 1.35 volts and the replacement alkaline batteries are 1.5 volts. Has anyone replaced their mercury batteries with the 1.5V alkaline batteries? Are there any known problems? Is anyone aware of a BMW recommendation or service bulletin on this subject? Thanks for your help.