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The U.S. DOT advises that any spare batteries should be stored in a zip-lock bag or the factory packaging to prevent short-circuits.  (Source: U.S. Department of Transportation)
New rules limit lithium content in batteries carried on aircraft

New rules went into effect today that could affect travelers who carry portable electronics on flights. The new regulations limit the amount of lithium in luggage and carry-on items -- specifically with regards to lithium in batteries.

The new rules state that spare batteries cannot be packed inside checked luggage, but spare batteries can be carried on board in carry-on baggage. Those brave enough to check baggage with electronic devices inside can leave installed batteries in the devices.

The U.S. Department of Transportation does not specify how many batteries are acceptable for travel.  The Department states passengers can carry spare batteries for electronic devices and that the lithium content in all batteries must weigh less than 25 grams.

To help explain the strange equivalent lithium content rule, Safetravel.dot.gov uses an example dividing the total amount of lithium as Watt-hours. The DOT claims lithium grams is roughly equivalent to 300 Watt-hours of battery time.

The popular Dell XPS m1330 notebook uses several different batteries. The 9-cell batteries, the largest available for the system, are rated at 85 Watt-hours. That would mean a pair of spare batteries for the notebook (170 Watt-hours) are well within the 25 gram (300 Watt-hours) total aggregate lithium content.   However, a passenger can only care the installed 9-cell battery with two spares before exceeding the 25g limit.

Devices that use lithium-metal batteries have a limit of two grams of lithium-metal per battery and according to Safetravel.dot.gov almost all lithium-metal batteries used in consumer devices comply with that limit. However, devices with lithium metal-batteries over the two gram limit are barred from the aircraft entirely.

These new rules are due to the potential fire hazard posed by rechargeable lithium batteries. The massive recalls and wide spread reports of fires resulting from laptop batteries resulting in the massive battery recalls of 2007 sparked the new battery policies now in effect.

However, the FAA is very clear on why such strict limits must be imposed.  In a statement released yesterday, the Administration stated, "Safety testing conducted by the FAA found that current aircraft cargo fire suppression system would not be capable of suppressing a fire if a shipment of non-rechargeable lithium batteries were ignited in flight."


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This article is over a month old, voting and posting comments is disabled

By TomZ on 1/2/2008 8:24:38 AM , Rating: 2
Nice post, however, it all hinges on some incorrect information:
quote:
Lithium batteries can cause fires when used correctly. These fires are rare. Lithium batteries can cause fires when shorted.

That is incorrect - these batteries will only cause a fire when they are defective. Under normal circumstances, it is impossible for them to catch fire during charge or discharge operations, including short-circuit. All these types of batteries have built-in protection against short-circuit as well as over-temperature that could lead to fire.

This is the reason why consumers can't buy these types of batteries (the raw batteries themselves) off-the-shelf - we can only buy ready-made "smart" battery packs. And when an engineer designs these types of batteries into a product, they work directly with the battery manufacturer to ensure that proper safety circuits are built-in.

Obviously, these safety measures are nullified when the battery itself is defective, but that is the exceptional case, not the normal case. And as I said before, if you look at the statistics (handful of fires compared to billions of batteries in use), the incidence of these fires is very very low.


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