Which lithium battery should not be used?

Which lithium battery should not be used?

• A. A dent on the casing.
• B. The battery is brand new.
• C. The label shows a different chemistry.
• D. A bulge on one side of the case.

Answer: (D)

A bulge on a lithium battery signals internal swelling from gas building up inside the cells. This is a serious safety risk because the swollen cell is under pressure and can vent, catch fire, or go into thermal runaway, especially if it’s charged or heated. For that reason, a battery with a bulge should never be used in a drone or charger; isolate it safely and dispose of it properly through the right channels. A dent on the casing might indicate damage, but it doesn’t confirm swelling. A brand-new battery is typically safe if it’s authentic and undamaged. A label showing different chemistry points to a mislabel or the wrong type of battery, which is unsafe for use, but the bulge is the most immediate hazard to avoid.

A bulge on a lithium battery signals internal swelling from gas building up inside the cells. This is a serious safety risk because the swollen cell is under pressure and can vent, catch fire, or go into thermal runaway, especially if it’s charged or heated. For that reason, a battery with a bulge should never be used in a drone or charger; isolate it safely and dispose of it properly through the right channels.

A dent on the casing might indicate damage, but it doesn’t confirm swelling. A brand-new battery is typically safe if it’s authentic and undamaged. A label showing different chemistry points to a mislabel or the wrong type of battery, which is unsafe for use, but the bulge is the most immediate hazard to avoid.