New reports were released today regarding instances of iPhones overheating and exploding. The reports highlight Consumer Product Safety Commission (CPSC) documents that include at least 15 reports of incidents with iPods and iPhones.
I am not a battery expert, nor have I seen the CPSC documents related to the iPhone and iPod incidents; however, based on my research of lithium batteries when looking into remote control helicopter recalls, I would not be surprised if it turns out that the iPhones and iPods in question had been dropped at some point, either during manufacture, shipping or use.
Lithium batteries, while lighter and able to pack more power into a smaller package compared to nickel-cadmium, are unstable and require special mechanisms to function properly. Should those mechanisms be disturbed, overheating, which can lead to fire and explosion, may ensue. Here are some of the facts:
• Lithium-ion is fragile and requires a protection circuit to maintain safe operation.
• The maximum charge and discharge current must be properly limited; overcharging is dangerous.
• The battery will become more vulnerable to failure if subjected to impact, crush or high rate charging.
• Lithium-ion Polymer, generally thought of as safer and more stable, is often compromised in commercial use to improve conductivity.
Although there are several other factors in the case of iPhones that could be causing issues, such as overworked processors, looking back on the numerous lithium battery operated products that have been recalled over the past several years, I again find myself questioning the safety of this power source in certain products. U.S. manufacturers and importers announced more than 30 lithium battery related recalls during the five year period from 2004 through 2008, involving nearly 14 million product units. While most recalls involved computer batteries, products ranging from bicycle lights to toys experienced problems. As a side note, it will be interesting to watch the safety reports of the many new lithium-ion powered cars.
With regard to CPSC documents that identify reports of iPhone failure, anyone can request such documents under the Freedom of Information Act (FOIA), but companies are afforded intellectual property protection. Therefore, if a company claims that documents expose proprietary technology or trade secrets, the documents will not be released. However, if it is true that KIRO-TV received documents from the CPSC as noted in the above referenced report, one could simply ask to see a copy of the documents already provided to the news station. There may be a fee associated with the physical copying or scanning, but the time to receive the documents should be less than the seven months reported by KIRO now that the documents already have been produced. Here is where to request the information: http://www.cpsc.gov/library/foia/foiaonline.html
Interestingly, because of new rules imposed by the Consumer Product Safety Improvement Act of 2008 (CPSIA), consumers soon may be able to find this type of information online. Sec. 212 of the CPSIA mandates that, "subject to the availability of appropriations," the CPSC must create an online searchable database of incident reports; information that currently must be formally requested under FOIA. Companies will still have an opportunity to claim intellectual property rights (though less likely to stick given that the information will be coming from consumers) and will be allowed to provide comments to be published alongside the reports. The database is scheduled to come online by August 14, 2010.
As for iPhone, regardless of what is in the CPSC documents, Apple has taken the possibility of dangerous overheating seriously enough to release an update that includes a temperature warning screen, though the temperatures are so extreme (less that 0 degrees F and greater than 113 degrees F) that most will never see the warning.
It may be too early to say whether the CPSC will require Apple to issue a recall related to iPhones. Nevertheless, as a practical matter, in addition to watching the ambient temperatures and heeding warning screens, if you drop your iPhone or iPod – or any other lithium battery operated device for that matter – consider replacing the battery, especially if you notice unexplained changes in charge cycles.
Here’s some general information from Apple on their lithium batteries:
http://www.apple.com/batteries/
And, here is some research on the pros and cons of lithium batteries:
http://en.wikipedia.org/wiki/Lithium-ion_battery
http://www.popularmechanics.com/technology/upgrade/4204202.html
http://electronics.howstuffworks.com/lithium-ion-battery.htm
