You can get battery with extended capacity. E.g. ZeroLemon have 10000 mAh battery: http://zerolemon.com/product/zerolemon-samsung-galaxy-note-3-10000mah-extend

You can get battery with extended capacity. E.g. ZeroLemon have 10000 mAh battery: http://zerolemon.com/product/zerolemon-samsung-galaxy-note-3-10000mah-extended-battery-with-nfc-zeroshock-shockproofdustproof-rugged-case/ http://zerolemon.com/product/zerolemon-samsung-galaxy-note-3... But phone becomes very bulky with it.