title_body: Is it safe to fly LiPo batteries after they get "puffy"? Some of my LiPo batteries got &quot;puffy&quot; after a few months. Is it still safe to fly them, or should I safely dispose of them?
upvoted_answer: You should dispose of them.
  
  A LiPo battery has three parts: the anode (negative plate), the cathode (positive plate), and electrolyte (sandwiched in between the two plates). Electricity is formed by electrons moving from the cathode to the anode through the electrolyte (which helps the electrons flow).
  
  The electrolyte decomposes over time, which results in the formation of elemental lithium and oxygen. Some of it combines into lithium oxide and sticks to the anode and cathode, but some of the oxygen remains a gas. This gas is what causes the puffiness you see.
  
  Oxygen likes to burn, so if you use a puffy battery, the likelihood that the moving electrons will ignite the oxygen is much higher, so once it becomes puffy, you should stop using it and dispose of it.