Swollen Li-ion Batteries

By Joe Callison
27 July 2022

Swollen Li-ion Batteries

A relatively recent phenomenon that is becoming more and more of a problem as our electronic devices have been designed to be ever thinner and lighter is a swollen battery. This is because the lithium-ion battery packs are no longer encased in hard plastic and are not designed to be user replaceable. They are thin, soft rubbery bags that are often glued in place and can only be safely replaced by professionals or very knowledgeable users. As a result, we don’t really think about them until they show serious signs of problems. If we are lucky, those signs are just a decrease in time they can run without charging, inability to hold a charge while not being used, higher than normal temperature when charging, or inability to stay on when the charger is unplugged. An extreme battery failure may even prevent the device from running, even with the charger connected.

As batteries degrade over time, they can produce a gas that builds up pressure inside, causing the soft enclosure to bulge out. When devices were built with more room inside, the bulge may not have been evident, unless the battery actually ruptured, which could result in a fire. Now products usually have little room for battery bulge and the thin, flexible devices will often show visible signs of distortion, or problems with keyboards or touchpads not working properly if the battery is pressing on their underside. Damage to internal components is likely in extreme cases. Continuing to use the device when bulging is evident or attempting to charge it can result in rupture of the battery and a fire. There have been multiple recalls of products with lithium-ion batteries that became swollen prematurely because of defects in manufacturing.


Current lithium-ion batteries in consumer electronics are typically usable for 3 or 4 years maximum before they show a serious drop in capacity (run-time). Battery longevity can be improved by not charging the battery to 100% or leaving it on the charger unnecessarily. Keeping the charge between 40% and 90% is ideal for maximum longevity. Smart battery technology in some Dell and Lenovo products are now using variable automatic charging control based on your typical usage. Some HP products will charge to 100%, but turn off charging until the battery drops to around 97%. Charging a hot device or leaving it in a hot car can destroy a battery or even cause a fire. Around 30 to 50% is the usual recommended charge for storage of batteries in unused devices for up to about 6 months. If storing for a year or more without checking the charge, then storing at nearly 100% might be necessary. You can expect a decrease in charge of about 20% per year of storage.

Batteries have low voltage protection to prevent the cells from getting so depleted that they are not able to recover. Devices usually shut down automatically long before the batteries get that low.

Fast charging is popular with consumers for electronic devices, power tools, and electric vehicles, but it is much harder on the batteries, and the batteries as currently designed will not last as long as they could at lower charging rates. The better-designed battery chargers only fast charge at the low battery charge condition and reduce the charging rate as the battery approaches full charge.

Lithium-ion batteries can be dangerous if damaged and must be disposed of properly. There are many stores selling batteries and electronic products that you can take old batteries to for disposal or recycling.

Posted by Joe Callison

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