I don't know about the Gigafactory 21700, but Sanyo/Panasonic has a commercially available 20700 with 247.19 Wh/kg, compared to 258.97 Wh/kg for one of their mo

I don't know about the Gigafactory 21700, but Sanyo/Panasonic has a commercially available 20700 with 247.19 Wh/kg, compared to 258.97 Wh/kg for one of their most energy-dense 18650s. Tests: http://lygte-info.dk/review/batteries2012/Sanyo%20NCR18650GA%203500mAh%20(Red)%20UK.html http://lygte-info.dk/review/batteries2012/Sanyo%20NCR18650GA... http://lygte-info.dk/review/batteries2012/Sanyo%20NCR20700B%204000mAh%20(Red)%20UK.html http://lygte-info.dk/review/batteries2012/Sanyo%20NCR20700B%...