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Is a swollen battery dangerous? YES!Updated 2 years ago

YES! A swollen battery is dangerous. Do not attempt to use or charge a swollen or otherwise damaged battery. Keep it in the fire resistant bag and take it to a recycle center ASAP. Google "battery recycle center near me" 

What causes the battery to swell?

The technical reason:

The polymeric nature of the electrolyte means that they also tend to produce carbon dioxide (CO2) and carbon monoxide (CO) when they decompose. The production of these gases is what causes a LiPo battery to expand and swell.


Normal everyday use of your battery will generate gas through a process called electrolyte decomposition. The electrolyte decomposition occurs even faster if you over-discharge a battery or overheat a battery.

Known causes for battery swelling:

  • Leaving the battery plugged into the charger after it has reached a full charge
  • Unevenly charged cells - the cause of this is not allowing the battery to charge to FULL - 
    • using the B3Pro charger - all three LED must turn green or the battery is not fully charged and an imbalance in the charge between cells is almost certain.
  • Allowing the battery to get too hot- such as it would get inside a parked car
    • attempting to charge a hot battery can damage it, causing the internal cells to swell - risking fire and explosion
  • Allowing the battery to get too cold and attempting to charge it before the battery's internal temperature is allowed to reach room temperature.
  • Over charging the battery - leaving it on the charger after it has reached a full charge
  • Over discharging the battery - using the battery longer than is recommended. 
  • Storing the battery fully charged - the internal gases can build up inside
  • Storing it in a place that is either too hot or too cold

CAUTION: The battery should always be allowed to come to room-temperature before charging. Charging a hot or cold battery might delay charging or damage the battery. For best results, charge the battery at temperatures between 50º and 80ºF (10º-30ºC).


The advice given above is general in nature and you are responsible for the safety of your batteries. SwiftPaws is not responsible for any direct, indirect, special, or consequential damages and personal injuries, including that to life, and health, resulting from the customer’s application and use of batteries sold by SwiftPaws.com.

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