Large external backup batteries are not new -- and in fact, there are many with a higher capacity than the BatteryBox (announced Tuesday, via TechCrunch). However, the BatteryBox has something the rest don't have: Battery OS, which company Gbatteries says provides better performance without battery-life degradation.
Specs on BatteryBox are 50Whr / 12,000 mAh. That is enough power to keep a Macbook Air running for 12 hours, a Macbook Pro for six hours, or to charge eight iPhones. As no degradation is part of its message, BatteryBox doesn't charge Macbooks, but instead bypasses the charging system and directly powers the Mac in order to minimize the battery memory effect.
BatteryBox comes with a MagSafe2 cord for charging current-generation MacBooks and MacBook Airs, but it also sports a USB port to power other devices; those devices charge normally.
The BatteryBox itself takes charges to 80 percent in about 4.5 hours; a full charge takes 9 hours. Input is via a microUSB port. Price-wise, it won't be cheap, and will be priced at 139 with the first units shipping sometime in the fall.
BatteryOS monitors and optimizes charging of the lithium-ion batteries inside the BatteryBox, which allows Gbatteries to claim 4x higher cycle life and 3,000 charge/discharge cycles with 96 percent capacity retained. Typical users can expect to get five years of use without any significant battery degradation, which is very impressive.
With many devices sporting non-user replaceable batteries (think iPhone and most tablets), battery degradation is a big problem. If BatteryOS works as advertised, expect that OEMs will be gathering to license the tech, or perhaps even acquire the company.