Lithium-ion (Li-ion) cells power smartphones and other mobile devices. These lightweight, portable batteries serve as the energy source for many devices because of their ability to charge up quickly. However, over time, Li-ion batteries can swell and expand. Have you ever seen or had a swollen battery in your mobile device and wondered what went wrong?

Here are some of the many reasons why you may have an expanded or swollen battery, what to do about it and how to prevent it.

Common Causes of Battery Swelling in Smartphones

A swollen battery is always an eyesore, altering your phone’s shape and eventually affecting the case. But what exactly causes this? A swollen battery is a clear sign that is too much current in a battery’s cells, ultimately resulting into a build-up of gas and heat.

An overload of current in the cells of a battery can result from several causes. Here are some of those common causes.


One common cause of a swollen battery is overcharging. Although it may not be solely responsible, leaving your phone plugged for extended hours and using the wrong phone charger may accelerate hazardous reactions between the electrolyte and electrodes, leading to a buildup of heat and gases.

Manufacturer Defect

Sometimes, poor design, low quality assemblage, mechanical damage, and other factory defects may lead to an anomalous buildup of gases and heat in the battery, making it to swell as time goes by.

High Temperature

Li-ion batteries cannot survive in extreme temperatures. If you continuously expose your smartphone to excessive temperatures, it may affect the battery health and lead to a swelling.

Deep Discharge

When you use your smartphone in any condition (such as continuous exposure to heat) that increases the self-discharge rate of its battery, your battery faces the risk of deep discharging, and subsequently,  swelling.


If your phone falls, it may damage the Li-ion battery inside, affect the chemical balance of its components, cause it to overheat and accumulate gas.

How to Prevent Swollen Batteries

Here are some tips to help you minimize the risk of bloated or swollen batteries.

Avoid overcharging your device. To function optimally, Li-ion batteries need to discharge and recharge. Keeping your phone plugged in for longer hours affect this charge cycle, overheats the battery and affect the overall health.

Use properly-rated chargers. When you need to replace your device’s original power charger, ensure you get the one with the same power output as the original.

Store your device in a cool, dry place. Avoid using your gadgets in extreme temperatures such as humid environments and hot cars.

What to Do When Your Battery Swells

Sadly, there’s not so much you can do to restore a bloated battery to a normal condition. If your device’s battery swells for whatever reason, the best way to go is to remove it ASAP and replace with a new one.

If the swollen battery is not removable, or you cannot remove it by yourself, take it to an authorized technician. An authorized repairer will look into it and replace with a new, functional one.

Swollen battery