I don’t really know who put Bluetooth on a padlock, but it uses a smartphone to open a lock with a free Master Lock vault eLocks application. So, if you forget your smartphone, it is possible to use a backup access with directional code on a lock keypad.
By the way, you can share access with others, either temporary or permanent, so if you want someone to open your padlock for any reason, you had better make sure that you trust them. For those are nervous about their lock, there is the possibility of getting some tamper alerts.
The application also tell you when the battery is about to expire, and replacing it with a CR2450. There is even a battery jump allowing for temporary access should the battery die.
So, if you want this, it will cost $49.99, and it will have a Limited Lifetime 1 Year Limited Warenty.