Battery Life
Equipped initially with a removable Li-Ion 620 mAh battery, the X400 offered adequate standby and talk times, with up to 260 hours of standby and 3 hours of talk time. An optional Li-Ion 900 mAh battery extended these to 380 hours and 5 hours, respectively. The removable battery design allowed users to carry spare batteries, ensuring they stayed connected even when unable to charge.