The Z1™ battery is designed to be charged and ready for use when you're on the go. To ensure that your battery maintains a full charge, first allow time for a full charge (up to 8 hours). Be sure that the AC adapter is fully plugged into the Powershell and wall outlet, and that the Z1 is in 'standby-mode'- meaning when the device is plugged in but NOT in use/ being used for therapy.
Once the battery is fully charged, be sure to disconnect it from the Powershell until you are ready to utilize battery power. For travel, we recommend allowing the battery to rest in the Powershell cradle, but not pushing the battery all the way in to connect to the Powershell. If the battery does stay connected in the Powershell, the charge will deplete over time.