The Iridium 9555 Rechargeable Battery is designed to be charged while inside the Iridium 9555 satellite phone. It can be used as a replacement for the 9555 battery or as a spare battery for extended travel.
To install a new 9555 battery as a replacement or spare, remove the current 9555. Install the new battery and charge for a minimum of 3 hours prior to use. Fast charge will be complete in about 3 hours 15 minutes.