Swollen Battery

A swollen battery is a lithium-ion battery that has expanded due to internal chemical degradation. Gases build up inside the battery cells, causing the battery pack to bulge or swell. Swollen batteries are a safety concern and should be addressed promptly.

Why Batteries Swell

Battery swelling occurs when chemical reactions inside the battery produce gases that can't escape. This happens for several reasons:

• Normal aging and degradation over years of use
• Exposure to heat (leaving MacBook in hot cars, direct sunlight)
• Overcharging due to faulty charging circuits
• Manufacturing defects
• Physical damage to the battery
• Leaving the battery fully discharged for extended periods

Once swelling begins, it will not reverse. The battery must be replaced.

Warning Signs

A swollen battery often reveals itself through physical changes to the MacBook:

• The trackpad feels raised or doesn't click properly
• The MacBook doesn't sit flat on a surface
• Gaps appear between case components
• The keyboard feels different or keys stick
• The screen doesn't close completely
• Visible bulging on the bottom case

If you notice any of these signs, inspect your MacBook from the side on a flat surface. Any raising or unevenness could indicate battery swelling.

Safety Concerns

Swollen batteries require careful handling. While they're generally stable, they can pose risks:

• If punctured, they can release harmful chemicals or catch fire
• Continued swelling can damage other components
• Pressure from swelling can crack screens or damage cases

This isn't meant to cause panic. Most swollen batteries are safely contained by the MacBook case and can be removed without incident by experienced technicians. The key is not to ignore the problem or attempt risky actions.

What to Do

If you suspect a swollen battery:

1. Stop using the MacBook - Don't continue using or charging it
2. Don't charge it - Disconnect from power
3. Don't try to flatten it - Don't apply pressure or force
4. Don't puncture or open it yourself - Unless you're experienced
5. Seek professional removal - Have the battery safely removed and replaced

Battery Replacement

Replacing a swollen battery restores your MacBook to normal operation. The swelling hasn't usually damaged other components unless it progressed significantly before being addressed. Professional replacement involves safely removing the old battery and installing a quality replacement.

If your MacBook is older, battery replacement can give it several more years of useful life. It's often the most cost-effective repair for aging MacBooks.