Battery or Battery Pack is Swollen or Bulging

Lithium (Li-ion, LiFePO4) Type Battery

Overview

Regardless of what caused the battery or battery pack to swell or bulge, it must be replaced. Do not use or charge a swollen or bulging lithium battery because it is dangerous and could leak, catch fire, or explode.

Reasons Why the Battery or Battery Pack Has Swollen or Bulged

• A malfunctioning battery management system (BMS) can cause a lithium battery to swell or bulge.
• An incorrect battery charger may have been used to charge the battery or battery pack. Using a charger designed for a higher voltage battery or battery pack will overcharge the battery or battery pack which can cause swelling or bulging. Simarlily using a battery charger that is not made specifically for charging lithium batteries can also cause battery swelling or bulging.
• The battery charger may have malfunctioned and overcharged the battery or battery pack.
• A short circuit in the electrical system may have overloaded and overheated the battery or battery pack.
• Physical damage such as punctures or impacts can short-circuit internal parts of the battery leading to overhaeting and gas buildup within the battery.
• Old age and normal use. Over time the electrolyte degrades and causes gas to build up within the battery.
• The battery could have a manufacturing defect which caused it to swell or bulge.

Steps To Take Before Replacing the Battery or Battery Pack

• If the battery leaked in the battery compartment, neutralize the spill with baking soda, then thoroughly wash and dry the area.
• Test the battery charger's output voltage to verify if it is functioning correctly and not producing too high of a voltage.

Safe Handling of the Swollen or Bulging Battery or Battery Pack

• Cover the exposed wire ends or terminals with electrical tape to prevent short circuiting during storage or transportation.
• If the battery or battery pack is wet or leaking, handle it with disposable plastic gloves and place it in a thick plastic bag to contain the leak.
• Bring the battery or battery pack to a recycling facility that accepts used lithium batteries.