The light Ooze pen displays red that means your battery needs to charge. How to charge it? Or how to know is ooze pen charging? Read on.

1. Unscrew the wax tank or the cartridge if you have been using a cartridge.
2. Then you take the Ooze charger out the package.
   You can see the specs on the back of the EGO style USB charger.
3. Make sure that both contact points clean and then you simply screw it on in.
4. How do you know when the ooze pen is fully charged?
   The red light will switch to green when fully charged.

OG Title: Ooze Pen Charging Instructions Slim Twist Pro 101: How to Charge (Battery)