Thermal runaway, cell rupture and combustion.

By Patricia Jordan

If you use a laptop computer, then you are aware that they generate a substantial amount of heat. Rechargeable lithium-ion (Li-ion) batteries can generate enough heat to ignite a fire and cause injury. Since the early 2000s, there have been many battery recalls for millions of rechargeable batteries that power computers, cell phones and other electronic devices.

The rechargeable Li-ion battery is one of the most popular types of rechargeable batteries for portable electronic devices. Over time, the capacity of all rechargeable batteries diminishes and most will fail without incident. If Li-ion batteries overheat or are overcharged, thermal runaway and cell rupture may occur and, in severe cases, even combust. To reduce these risks, Li-ion batteries contain circuitry
that shuts down the battery when its voltage is outside the safe range. While the risk with Li-ion batteries is real, I do not want to give the impression that laptop computers, cell phones and other electronic devices are unsafe to use.

In May 2011, as I was working with my MacBook Pro I heard a noise and felt the computer lift. After turning it over, I was surprised to find the battery was bulging, it had burst. Thankfully, the battery was not leaking and did not damage my computer and I was able to safely remove it. This experience alerted me to the dangers of rechargeable Li-ion batteries. Apple replaced the defective battery at no charge.

My online search for the cause of the rupture lead me to YouTube and several alarming videos of laptops in flames. Search for “Laptops in Flames.”

Now, I use electrical power for my laptop and only use the battery when I am away from a power source. It is important to disconnect your laptop power adapter as well, as they can also overheat and catch on fire. Cell phones and other electrical devices have also caught on fire because of rechargeable Li-ion batteries.

All rechargeable Li-ion batteries will eventually wear down and hold a charge for less time. A battery will work one day and lose its ability to maintain the charge the next day. Rechargeable Li-ion batteries usually last two to three years, even if they are unused. Check the manufacturing date on the battery to ensure it has not been sitting on a store shelf for several months.

A change in the Li-ion battery life span, such as not lasting as long as it usually does is an indication that one or more of the cells has failed. If a cell develops a short, it could damage other cells within the battery and your electronic device as well. When this occurs, it is best to purchase a new battery and recycle the used battery
at a reputable recycle depot. The CBABC website contains an index of recycling resources in British Columbia at www.cba.org/BC/Practice_Resources/business/recycling.aspx.

Did you know?

• Google stores search requests for 18 months.
• Facebook, LinkedIn and MySpace are often targeted by cyber-criminals seeking personal information supplied by users.
• Facebook, Myspace and YouTube are the top three blocked websites by corporate network firewalls.

Sites Du Jour

Visit How Stuff Works to learn more about lithium-ion batteries.

SeatGuru.com provides comparison charts that identify airlines and airplanes with in-seat laptop power. See “The Ultimate Guide to In-Seat Laptop Power Ports.”

This article was published in the August 2011 issue of BarTalk. © 2011 The Canadian Bar Association. All rights reserved.