Without a battery or MOD your e-cigarette will essentially be useless; and that's obviously not good. So what do you need to ensure that your electronic cigarette is always fully functional? A battery. A good battery will provide you with hours and hours worth of power, allowing you to vape away all day. Whether you're using the ego style or IMR batteries having top quality batteries will give more power to your e-cig providing you with a better taste, more vapour and longer usage.