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.

Charging

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.


Safety
 
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. 

Terms & Conditions

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 that have been out of service for greater than six (6) months.
-Always charge/store Batteries in a non-conductive, fireproof container or bag.
-For best results, store Batteries at approximately 1/2 of the capacity listed on the batteries’ label.

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 Batteries is connected to the positive terminal of the charger. Confirm polarity with a voltmeter if unsure.
-Check the voltage of Batteries using a voltmeter to make sure Batteries have the voltage of the capacity listed on Batteries’ label.

Charging
Always 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 balanced mode charger, specifically designed for the chemistry of battery you are using.
-Always charge Batteries in an open area away from flammable materials, liquids and surfaces.
-Never charge Batteries inside of the model.
-Never charge Batteries that are hot to the touch (above 100F) DO NOT handle batteries until they are cool.
-Always set the charger to proper cell count and/or voltage listed on Batteries’ labels.
-Never charge at a rate greater than 1/2C (Half the capacity of Batteries in amp hours)
-Always check the voltage of Batteries before each charge session in order to ensure they are at or above the minimum safe starting voltage. If starting voltage is below recommended levels than Batteries have been over discharged or have experienced a failure and should NOT be charged.
-Never overcharge Batteries beyond the capacity listed on Batteries’ labels.

Safety 
If an 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 in an approved Li-Po bag to observe. After one hour, remove the Batteries from service. 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.
-Never discharge batteries to voltage below which they are rated by the manufacturer when measured under load (connected to the vehicle or a charger capable of discharge). Batteries discharged to a voltage lower than the lowest approved voltage may be damaged, resulting in loss of performance and potential fire when Batteries are charged.

Additional Guidelines and Warnings
-In the event of a crash, always quickly and safely disconnect and remove Batteries from the model. 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. 

Battery Limited Warranty - NOTICE
All instructions, warranties and other collateral documents are subject to change at the sole discretion of UNO. For up to date product literature, visit www.unobatteries.com

Warranty Period
Exclusive Warranty - UNO warranties that the Products purchased (the “Product”) will be free from defects in materials and workmanship at the date of purchase by the Purchaser. 

Limited Warranty 
UNO reserves the right the change or modify this warranty without notice and disclaims all other warranties, express or implied
This warranty is limited to the original purchaser (“Purchaser”) and is not transferrable. REPLACEMENT AS PROVIDED UNDER THIS WARRANTY IS THE EXCLUSIVE REMEDY OF THE PURCHASER. This warranty covers only those Products purchased from an authorized UNO dealer. Third party transactions are not covered by this warranty. Proof of purchase is required for warranty claims.
Limitation - UNO MAKES NO WARRANTY OR REPRESENTATION, EXPRESS OR IMPLIED, ABOUT NON INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OF THE THE PRODUCT. THE PURCHASER ACKNOWLEDGES THAT THEY ALONE HAVE DETERMINED THAT THE PRODUCT WILL SUITABLY MEET WITH REQUIREMENTS OF PURCHASER’S INTENDED USE.
Purchase Remedy - UNO’s sole obligation hereunder shall be that UNO will, at its option, replace any product determined by UNO to be defected in the event of a defect, this is the Purchaser’s exclusive remedy.
Replacement decisions are at the sole discretion of UNO. This warranty does not cover cosmetic damage or damage due to acts of God, accident, misuse, abuse, negligence, commercial use, or modification of any part of the product. This warranty does not cover damage due to improper installation, operation, maintenance or attempted repair by anyone.

UNO DOES NOT INSPECT OR REPAIR BATTERIES, NEVER SHIP BATTERIES TO UNO.

Damage Limits
UNO SHALL NOT BE LIABLE FOR SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES, LOSS OF PROFITS OR PRODUCTION OR COMMERCIAL LOSS IN ANY WAY WITH THE PRODUCT, WHETHER SUCH CLAIM IS BASED IN CONTRACT, WARRANTY, NEGLIGENCE, OR STRICT LIABILITY.

Further, in no event shall the liability of UNO exceed the individual price of the Product on which liability is asserted. As UNO has no control over use, setup, final assembly, modification or misuse, no liability shall be assumed nor accepted for any resulting damage or injury. By the act of use, setup or assembly the user accepts all resulting liability.

If you as the Purchaser or user are not prepared to accept the liability associated with the use of this Product, you are advised to return this product immediately in new and unused condition to the place of purchase. 

Law: This Agreement shall be construed, interpreted and enforced according to Arkansas law, WITHOUT REGARD TO CONFLICTS OF LAWS PRINCIPLES, in any litigation, arbitration or legal proceedings arising out of this Agreement.