A spare battery for e-cigarettes (industrial battery type 18650) is bursting in flames. Image: Empa
E-cigarettes often draw their energy from lithium-ion batteries of the type 18650, but these batteries are extremely dangerous without a protective cover. Empa scientist Marcel Held demonstrates this fact with an experiment on the program «Kassensturz» of Swiss television SRF. The take-home message: Whoever carries such batteries loose in his pocket lives dangerously.
The SRF program «Kassensturz» on 23 January 2018 reported about a man who suffered severe burns to his thigh due to the exploding battery of his e-cigarette. He had kept the spare battery for the e-cigarette in his pocket, along with coins and a bunch of keys. This caused a short circuit; the battery turned into a flame thrower.
Empa’s battery expert Marcel Held reconstructed the situation in his chemistry lab for the SRF television team: He removes the insulation film from a standard size 18650 lithium-ion battery and places the battery in a beaker full of screw nuts. Behind a protective screen, in a laboratory fume cupboard, Held then fills the beaker with some Swiss 5-rappen-coins. The upper contact of the battery, which was previously free, gets connected thereby. A short-circuit occurs, and after a mere 10 seconds the battery ends its life in a flame of 30 centimetres length.
Only intended for installation in battery packs
Standard size 18650 batteries carry the warning «DANGER – DO NOT USE OUTSIDE OF BATTERY PACK». Such rechargeable batteries are only intended for installation in battery packs of laptops, power tools, e-bikes or cars. They should not be used or transported without a protective extra shell. The 18650 standard rechargeable battery is insulated just with a thin plastic film. If the insulation at the upper end of the battery cylinder is getting damaged, e. g. by a key, a single coin is sufficient to short-circuit the positive pole with the battery housing. If you carry such batteries unpacked in your pocket or handbag with you, you are definitely in danger.
Source: EMPA