Anker Powercore Select 20000: The ultra-high capacity portable charger with a 20,000mAh capacity, you can easily keep all of your mobile devices charged up for days on end. You'll wonder how you ever spent so much time plugged into the wall. Our exclusive charging technology intelligently identifies your device’s requirements to deliver an optimized charge. Fully recharge your PowerCore in just 5 and a half hours when paired with an 18W charger (not included). Anker’s exclusive MultiProtect safety system ensures complete protection for your devices.