Interestingly, I just received this in the monthly Dealer Newsletter. I guess I wasn't the only one
Tip of the Month
During the recent cold spell we received many calls from people having trouble starting their cars. Although many of the cars were newer, the issues all boiled down to battery voltage. Many years ago we plugged in our vehicles using a block heater to ensure successful cold starts. We no longer use block heaters on our vehicles, but with cold temperatures, we have to take care of the battery, to best ensure successful starts. Because of all the comfort options, like heated seats, heated steering wheels, heated mirrors and rear defrosters, many of our clients who only drive very short distances have starting issues in cold weather. To solve this problem, BMW has a Battery Tender which, when installed, will keep the battery charged.
In most cases 2 or 3 overnight charges during very cold ambient temperature will be sufficient. The charger can be permanently installed into your car or kept as a stand-by. For a low cost and little effort you can make sure your car will start in any temperature. This charger is also recommended for complete vehicle storage. Just plug in when you put your vehicle in storage and unplug when you start driving your BMW again. The battery will be at full strength without disconnecting.
So the take home here is that we have an app for that?
I understand the concept of keeping a battery on a trickle charger, my motorcycle is on one during winter. Nevertheless, I still have a hard time directly correlating the demand from the accessories and depleting the battery without somehow having doubts about the charging system as a whole.
Again, my warnings started way before the cold weather....