Norsk Lithium MAX 11.1V Green Series Batteries W/Built-in USB and Meter - Norsk's best-selling all around battery. This Ultra-Lightweight battery is the best on the market for cutting pounds. Don't store your battery for the winter. NORSK batteries include a patent pending LED indicator and Dual USB accessory ports! Keep your phone charged and power accessories during all of your outdoor adventures. Built-in LED Battery Level Meter Dual Built-in USB Ports 2X Power of Lead-Acid and Half the weight