How do I charge my Olumat Latch Lock?

How do I charge my Olumat Latch Lock?

The Olumat smart lock uses 4 AA batteries for power and cannot be charged. If the batteries die, there is a charging port on the underside of the keypad half of the lock. With a power bank, you can power up the Olumat smart lock once to open it electronically and then replace the batteries.