Kyberlight uses a rechargable Lithium Ion Battery to power the V5 saber. As with all Lithium Ion batteries, charging to 100% and draining to 0% actually hurts the longevity of the battery pack. In order to lengthen the life of your battery, the charging circuit we use is set to charge the saber quickly from 0-90% and then very slowly until full (97-99%). This means that most of the time your saber will not reach full charge by the time you would like to use it. It also means that often the battery, even if left on the charger overnight, will not reach a 100% full charge (when you check the battery indicator) in order to preserve the life of the battery. With this in mind, the saber should still be giving you about 2 hours of continuous use. If you are charging the saber for more than 2-3 hours and only getting about 1 hour of on-time or less, please reach out to us to get a repair going.