My question is what would they be fighting over if Panasonic made both? Panasonic does make both don't they ??

http://www.renewableenergyworld.com/articles/2015/09/panasonic-and-tesla-poised-for-battery-fight-in-europe.html?cmpid=renewablestorage09102015&eid=291113142&bid=1173076

Unless someone else is making the Powerwall battery. Then this headline makes sense !

Maybe it is the new cell type "M".