The Iridium 9555 High Capacity Battery provides up to 6.5 hours of talk time and 43 hours of standby time for the Iridium 9555 satellite phone. This low-profile, 3760 mAh lithium-ion battery is specially designed for the Iridium 9555 and is easy to install and remove. It has a charge time of 4 hours and can operate in temperatures from -20°C to 60°C (-4°F to 140°F). The battery voltage is 3.7 V. This battery pack contains no hazardous materials and is recommended for use with cellular phones.