The vehicle battery is connected to the fuse box via a heavy duty cable. It has been determined that the cable connection at the fuse box can degrade over time, resulting in increased electrical resistance. This increased resistance can cause the connection point to overheat and break, resulting in a loss of electrical power and causing the engine to stall, increasing the risk of a crash. Dealers will replace the positive battery cable connector and secure it with an improved method to correct this concern.
 
Recalls
Recalls are issued for cars with safety-related defects or problems
2011 BMW Z4 sDrive
The Battery Cable Connection at the Fuse Block May Break
Electrical & Lights, February 7, 2013