Lithium Ion batteries store a ton of energy, and while these can endure hard impacts, long drains of high power, etc, they do have their limits, and if pushed too hard or are not used properly, they can be very dangerous.
How to be safe
As a general rule, if you store them 30% charged in a cool, safe place away from anything flammable, use only a Lithium charger (both LiPo or Lithium Ion chargers will work fine) charge them slowly and under supervision, discharge them at the rated C-ratings with proper ventilation / cooling, treat them nice and don't do anything crazy like shorting them out or crushing them, they will not cause any issues and last a very long time.
The full legal disclaimer is under tab above
:Warning: procedures, which if not properly followed, create the probability of property damage, collateral damage and serious injury. For the purposes of this document, Li-ion will be described as “Batteries”.
Handling and storage
-Never alter, puncture or impact Batteries or related components. -Do not directly connect the terminals with metal objects. This will short-circuit Batteries, resulting in heat and electrical discharge. -Never store loose Batteries together, the Batteries’ terminals may contact one another causing a short circuit. -Never expose Batteries to extreme temperatures or direct sunlight. The temperature range must be between 40-120F (4-49C). -Always verify voltage of Batteries using your UNO app that have been out of service for greater than six (6) months. -Always charge/store Batteries in a safe place away from personal property. -For best results, store Batteries at approximately 50% charged.
Before the First Charge -Make a visual and physical inspection of Batteries for any damaged or loose leads or connectors, damaged packaging, or other irregularities which may cause a short circuit and eventual fire. -Verify that the positive terminal of the junction box is connected to the positive post of your charging port.
ARAlways refer to your charger’s manual for correct procedures and safety information. In addition to your charger's manual, the warnings and guidelines listed below must be followed to avoid possible property damage and injury. -Always use a compatible listed approved UNO charger with a max charge voltage of 58.8V. DO NOT LEAVE CHARGER ON AFTER BATTERY IS FULLY CHARGED. Leaving a battery and charger connected after a full charge is reached is not recommended regardless of battery type or charger. For the most up to date list of approve chargers see www.unobatteries.com -Always charge Batteries in an open area away from personal property.
If at any time Batteries become damaged, hot or begin to swell, discontinue charging or discharging immediately. Quickly and safely disconnect the charger. Then place the Batteries in a safe, open area away from flammable materials to observe. Do NOT continue to handle attempt to use, or ship the Batteries. Failure to follow these procedures can cause damage to Batteries, personal property or cause serious injury. Damaged or swollen Batteries can be unstable and very hot. DO NOT touch Batteries until they have cooled. Dispose of Batteries in the manner required by your city, county, state or country. In the event of a fire, a Class D, dry chemical fire extinguisher must be used.
Discharging -Never discharge Batteries at amperage rates higher than specified on Batteries’ labels. -Never allow the temperature of Batteries to exceed temperatures advised by the manufacturer.
Additional Guidelines and Warnings
-In the event of a crash, always quickly and safely disconnect and remove Batteries from the vehicle. Then follow the previously listed safety procedures. -In the internal contents of Batteries come into contact with your skin, wash the affected area(s) with soap and water immediately. If it comes into contact with your eye(s), flush them with generous amounts of water for 15 minutes and seek medical attention.