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What causes a battery to swell?Updated 2 years ago

Please do not attempt to charge or use a swollen battery. Keep it away from anything flammable and take it to a recycle center ASAP. Google "battery recycle center near me" - most places that sell batteries will take batteries for disposal. 

Get a picture of the battery before disposing of it and include the picture when you email [email protected] if you are making a warranty claim.

What causes the battery to swell?

Preventable causes:

  • Leaving the battery plugged into the main drive unit when not in use
  • Not charging the battery to full before each use
  • Leaving the battery on the charger after it has reached a full charge
  • Allowing the battery voltage to drop below the minimum charge
  • Allowing the battery to get too hot (leaving it in the car or a hot garage)
  • Not allowing the battery to come to room temperature before charging
  • Using the battery before the charger indicates a balanced charge

Technical explanation of what happens to make the battery swell:

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.

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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