The SPIRIT is a wearable and water resistant device. In order to be as light and elegant as possible, every part - including the battery- is designed to be as small as possible. The battery of a smartwatch this size needs a daily charging routine that fits your situation. The battery life further depends on the strength of the mobile networks in your region. The SPIRIT petite, being even a bit smaller, shows a battery life time difference with the regular SPIRIT of 2 - 4- hours.