My F10 535i had the same message once last year. I have been using Schumacher XC103 smart charger to charge the battery once every month. Sometimes I leave it being charged overnight. Now, the battery performs substantially better. I never saw the message again.
It works even better on my old Tacoma pickup truck. The new high-capacity battery in the truck would die in just 3 days if the truck was not driven. I used another cheaper battery charger on it a couple of times and it made no difference. Then I used the XC103 to maintain the battery for 3-4 times. Now, the battery can last 5-6 weeks without truck being driven.
It has become a second nature of me to charge the batteries for all the vehicles in my fleet once a month. Modern vehicles have too many electric devices which put a great pressure on the battery.