We have often heard about bad experiences with battery-powered tools or small powerbanks. One more argument in favor of our E-Series: unlike most smaller, older battery-powered devices, we use lithium iron phosphate battery technology, which is characterized by its high cycle stability. That means even after 2,000 charge cycles, an effective capacity of more than 80% should be available in most cases. Even with a daily charge of the battery, the device can thus remain ready for use for over 6 years.