How to Safely Charge Your Vape How Long to Charge a Disposable Vape? Cannabis Life Vapers quick warning If you vape and use the same charging cable for your vape pen and your phone, you could be putting your phone at risk Vape 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.