What is the Difference Between Built in or Separate Cell Batteries?

Built in

If the batteries do not come out then use the usb lead provided with the device (Always use the provided lead for safety reasons) Not all usb leads that look the same are the same. The reason it is fine is because the manufacturer has tuned the charging for the exact cell they have used and the exact lead they have provided.Just make sure you are present when it is charging and do not leave them over night. Alway use a plug that will put a slow charge in if you can 1 amp preferably but if it gets hot use a plug that charges slower. If in doubt ask your local store Examples of batteries or mods with built in batteries

Separate Cells

It is not recommended that users charge their separate cell devices with a usb lead in to the device. These devices can be charged via usb as an emergency measure but is not recommended as a permanent solution. This is not a line to sell chargers there are significant reason why it should be done externally. Do not assume that it is safe. These batteries are not made for vaping and the manufacturer has no idea what cells you are using. Best to use the safer solution of a named quality charger. Hint: if it has fire in the title it probably isn’t the safest for high drain vaping ie 30 watts plusExamples of mods that take external cells