A new portable battery promises to carry enough juice to charge eight iPhones and keep your MacBook Air going for 12 hours, five years after you buy it. Unlike others that lose their capacity over time, BatteryBox uses a new energy management system called BatteryOS that monitors what's going on inside your Lithium-Ion battery and optimizes power in such a way that prevents degradation. It's an operation that ensures the battery can handle 96% of its original capacity after 3,000 charges and discharges, almost twice as long as without the system says BatteryBox. And it does it all for $139, about what you'd pay for a competitor. BatteryBox's 12,000mAh battery is the first implementation of the technology, but the company hopes to work with third-parties to get its system into things like electric vehicles. For now, we're just excited to see a portable charger that can keep us churning out posts from the outlet-free wasteland of CES through 2020.