Lithium-Ion batteries should never be kept loose in your pocket or purse. Always use the case provided.

Lithium-Ion cells should be charged on a dedicated charger rated specifically for Lithium-Ion cells.
Never leave a battery unattended whilst charging.
Keep away from animals and children.
Wraps and insulators should be periodically inspected for tears or damage. If a battery has a damaged wrap, it should be repaired or disposed of immediately.
If you are re-selling these cells, it is your duty to pass these warnings onto your customers.
Batteries usually have a cycle life of between 200-500 cycles (varies with manufacturer) before noticeable capacity drop off. Batteries should be recycled at this time.
Do not crush, incinerate or modify.
Only use within manufacturers specification.

Molicel P28A 18650 Battery