Mugen Power Extended Battery w/ Battery Cover for AT&T Mobile Hotspot Elevate 4G / Sierra Wireless 754S Mugen Power Extended Battery w/ Battery Cover for AT&T Mobile Hotspot Elevate 4G / Sierra Wireless 754S 5,800mAh, 3.7V power rating; Lithium-ion technology Provides more than double the capacity of the standard battery Comes with an extended battery cover door that accommodates the extended battery Keeps your phone charged and ready to go, even with heavy phone and data usage