Introduction

Mobile devices are built to maximize how long they can run between charges by topping off the battery when connected to power.  However, in mobile device and Continuous Integration (CI) labs, where hundreds of devices need continuous USB data connections, this presents a challenge. When these devices are USB-tethered for extended periods, the battery is held at a high state of charge (SoC). Long-term high SoC can cause battery swelling and ultimately lead to device failure.

Seeing your battery swell after years of using a phone or laptop can be a scary sight, but knowing what to do if it happens and recognizing the early signs of battery swelling is essential for your safety.

Several factors, including wear and tear on the lithium-ion cells within the battery and leaving a laptop or device plugged in continuously for days, weeks, or years can contribute to battery swelling.