Car would not start; battery was too low to activate lights or locks, let alone starter. An attempted jumper cable connection to an older car was insufficient to make the motor turn, even after just running the assist car while connected for 20+ minutes. A subsequent jump from the AAA 2000 Ah jump pack did work although their -??test-?? indicated battery state-of-charge and state-of-health to be less than 30%. Their obvious recommendation was battery replacement and, with the vehicle now running, a drive to the dealership was attempted. At the first intersection a full vehicle stop engaged the engine Stop-Start function, but without sufficient battery for the -??Start-?? part. Not only would the vehicle not restart but there was insufficient battery power to put the transmission into PARK nor engage the emergency brake to prevent the vehicle from rolling into busy cross-traffic; only the service brake worked. Fortunately, a nearby motorist recognized the emergency and placed rocks under the tires to prevent the vehicle from rolling forward. The vehicle was towed to the dealership where the battery was replaced without significant comment on the total failure of nearly all systems in the event of battery failure. The outcome of this major battery failure could have been catastrophic as the ONLY system even marginally functional was the non-power-assisted service brake.

- Tucson, AZ, USA