Anker PowerHouse 511: The ultra-powerful portable charger. 24,000mAh of charging power ensures over one complete charge for the MacBook Air and a significant battery boost for other laptops. Depending on battery size, most smartphones will get over 4 full charges with tablets also charging at least once. The built-in AC outlet uses a pure sine wave inverter to ensure the power output is just as good as what you get at home. Reduces audible and electrical noise in sensitive appliances. Never be left in the dark again. Choose between full brightness, low brightness, and SOS lighting modes at the push of the button.