To charge a vape battery safely charge them in a lithium ion charger. Always charge your device or batteries in accordance with the manufacturer’s instructions. If you are charging by plugging into a wall socket, make sure you are using the supplied charging lead. If you are charging loose batteries, use a quality lithium-ion battery charger. Never charge devices and batteries overnight while sleeping or leave them unsupervised. Never use a battery with cracked or torn wrapping. Inspect your cells before use and if you see any surface damage replace the wrap immediately.
Loose batteries must never be carried in pockets or bags. Always make sure you carry them in a dedicated battery case to keep them from short circuiting.