My husband use's these USB E cigarette chargers all the time , these ones are a pack of three and are the type you screw onto the battery and the input is Input: DC 5V Output: DC 4.2V Battery Size 650mAh-1300mAh, CE Approved and the lead is 23cm
Excellent quality , so easy to use plug in and uncharged the light is red and fully charged the light is green . I think these are excellent value for money and now my huband can have more than one battery charging at a time .
for more information or to purchase please click the link below
https://www.amazon.co.uk/HAVILAH-TECHNOLOGIES-Cigarette-Electronic-Atomizers/dp/B01M0XBXOV