Always charge in/on a fire-proof surface.
Never leave charging batteries unattended.
Do not modify batteries/chargers in any form or shape.
Do not misuse or mishandling of 18650 / 26650 Li-Ion batteries and the chargers.
If there is any signs of damage on your charging devices please discard them as its not worth the risks associated to continuing charging of that device.
The picture below gives a great quick guide to the do's and dont's that go along with battery usage. Please keep in mind there are very serious consequences to not understanding or following these guidelines
18650 up to 26650 Batteries are able to be charged by all the vape chargers above. And they are all reputable charger companies with Golisi making themselves a vaper dedicated supplier which is fantastic.