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 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.