FAA Reports Heat In Cargo Holds Can Ignite Laptop Batteries 103
SpuriousLogic writes "US aviation officials are warning air carriers that new research shows lithium batteries are sensitive to heat and can ignite in-flight if transported in cargo compartments that get too hot. The Federal Aviation Administration also acknowledged publicly for the first time Friday that a United Parcel Service 747-400 plane that crashed in Dubai last month killing both pilots was carrying a large quantity of lithium batteries. Since the early 1990s, there have been dozens of incidents of batteries igniting in flight. But it has not been known what triggered many of the fires. FAA now says recent research has identified heat as the trigger and is offering air carriers advice on how to reduce the risk of fire."
TFA Says nothing about laptop batteries (Score:5, Informative)
Metal Lithium batteries!=Lithium-Ion batteries used in laptops. Metal Lithium batteries are too dangerous to be used in laptops.
Re:TFA Says nothing about laptop batteries (Score:2, Informative)
In other words, this article has absolutely nothing to do with laptop batteries.
A simple search for Lithium vs Lithium Ion [google.com] leads to explanations of differences between the two.
Re:Last time I looked (Score:4, Informative)
it depends on which cargo hold your stuff is put in on an airplane. On my aircraft, the forward hold is heated & pressurized, and the aft hold is not.
here's how the bins (as we call them) are pressurized/heated. the air that comes out of the packs is routed through the cabin, then flows through the cargo bin before being dumped overboard through the pressurization valve. so while the bin is heated, there is no direct control of the heat like the cabin. we have charts in our manuals that will tell us the temp of the bins based on the outside air temp, so we can tell whether or not its safe to put Fido in the cargo, but otherwise we have no direct way of monitoring the cargo compartment temp.
Re:TFA Says nothing about laptop batteries (Score:5, Informative)
Basically what this says is, a fire in a cargo compartment could easily heat lithium batteries to the point that they cause explosions and large secondary fires. Also, the fire suppressant commonly used in cargo bays may not control a lithium fire. Thirdly, shorted lithium batteries may get so hot that they ignite other materials around them, even if they don't catch fire themselves. Lithium-Ion batteries are also mentioned, basically restating the above but suggesting that existing fire suppression can more easily control a fire from a lithium-ion cell.
In the end, the recommendation is to change reporting rules so that lithium batteries in cargo must be reported to the pilot in command. Effort should be made to carry them in cargo bays with sufficient fire extinguisher capability. Also mentioned is storing them in containers designed to keep fire or explosion contained, and that existing containers will not do this.
It is even specifically noted that this advisory applies to bulk shipments and does not include batteries brought aboard by passengers.
Re:RTFA? (Score:4, Informative)
Re:So that is what happened to my batteries... (Score:3, Informative)
I typically travel with more cables, chargers, and batteries than you can shake a stick at (Two cameras, an iPhone, a laptop, a hiking GPS and an Nuvi.) I've never been pulled for extra scrutiny - except the one time I was headed home for a funeral and had only my cell phone and laptop. I.E. don't try drawing a curve through a single data point.
Never mind you have absolutely zero evidence that is true.
Re:Last time I looked (Score:5, Informative)
How hot are we talking about? The safe maximum operating temperature for discharging a Lithium ion battery is typically 140 degrees Fahrenheit. There's no place on Earth that gets that hot naturally....
The notion that heat in cargo holds might ignite laptop batteries is patently absurd unless the cargo hold is on fire. It's more accurate to say that heat from an actively failing battery can start nearby cells on fire, which is a great big "duh".
Lithium ion battery fires are usually caused by dendritic growth [gizmag.com] inside the cell. There's no good way to determine when this might occur short of scanning electron microscopy, and there is no safe temperature at which this is not a problem....
The only time heat is a factor in Lithium cell failure is typically during a charge cycle (or occasionally during a very fast discharge cycle), when temperatures shoot way up into the mid 100s Fahrenheit. If they go way outside that range, they can go through thermal runaway.
That said, the charge circuits in the battery packs normally make this impossible unless a cell is defective. They shut down in such a way that the pack cannot be charged if the cell voltage drops below a minimum threshold because the charge current required would be high enough to pose a fire risk. Similarly, they disable charging above a maximum threshold to keep the batteries from becoming overcharged.
In short, if these things are burning up in flight, the cells were defective to begin with, period, and odds are good that they were improperly charged, too. There's just no way the cargo hold of an airplane gets hot enough to be a problem unless one of the cells shorts out internally, at which point the temperature really doesn't matter much anyway.