HyperJuice: The Most Powerful USB-C Battery Pack
To achieve the maximum battery capacity of 27000mAh, we used 8 x LG Chemical 18650 Rechargeable Lithium Ion Battery Cells. We narrowed down to 2 possible battery cell configuration and ultimately went with configuration/prototype #2 as it is slimmer, enough to fit in bags/pockets and easier to grab/hold with a single hand.