A trackpad that pops out or bulges on a laptop is often a warning sign of a swollen lithium-ion battery, a fault that can render the device unusable and, in rare cases, pose a fire risk. Since the battery typically sits directly beneath the trackpad in most modern laptops, including MacBooks and Surface devices, chemical degradation from overcharging or physical damage causes it to expand and push components outward, meaning users who notice this should stop using the laptop immediately and seek professional repair rather than attempting a fix themselves.

Lithium-ion batteries are generally safe but can release harmful gases and swell when overcharged or damaged, and a trackpad popping out is usually a sign the battery is nearing the end of its life, a problem serious enough that Apple has previously run replacement programmes for affected MacBooks. Repair costs vary, with Apple charging between $149 and $249 to replace a MacBook battery depending on the model, though devices still under warranty are typically repaired free of charge; users are also advised to avoid extreme temperatures, use certified chargers, and store unused laptops at around 50% charge, checking them periodically.