Why do some vapes allow use while charging and others do not? How To Safely Charge An E Cigarette Unplug your vape when it's fully charged to reduce the risk of fire. Rechargeable vapes contain batteries which can overheat when left charging for too long and that means fire risk. Many devices like vapes, power tools and toys use lithium ion batteries, and if they are damaged or charged incorrectly, they can cause a violent fire within seconds. Here are some tips to