eGo-T 650 mAh Battery (with safety) BLACK, 3.7 volts. Press button 5 times repeatedly to turn on, press button 5 times repeatedly to turn off. Very cool feature! This battery will give you 6-8 hours of battery life. We actually get longer than that on average. For use with any 510 or eGo atomizer or cartomizer. These batteries come fully charged, so vape right away!! For use with any 510 or eGo atomizer or cartomizer. Gives you tons of options!(A charger is not included with this battery, however can be purchased separately in our charger section or in related items below this description. You would need the eGo Fast USB charger. If you want to also charge it in the wall, the USB to Wall charger would also be needed).