Installation of the battery.
The battery may not be installed in the unit when it arrives. To install the battery, remove the protective padded case around the unit. There is a Velcro strip between the padded case and the unit housing.
Separate the Velcro strips and the housing can be removed. At the opposite end from the display panel, there is a sliding door that must be opened exposing a channel compartment for the battery. The battery must be placed into the channel with the silver contacts toward the opened door. Push the battery into the channel until you feel resistance and the door can be closed. Place the housing back into the soft case for protection.