I just returned from five weeks of travel in China, Hong Kong, Cambodia, Thailand, and Vietnam, including internal flights on the execrable China Eastern as well as Dragon Air, Vietnam Air, and Bangkok Air.

All airlines are posting what appear to be insane rules concerning lithium batteries in checked and carry-on luggage. I can't hope to accurately synopsize them here, but I observed these rules to be utterly randomly enforced, and once I became familiar with them, utterly inscrutable.

Let me state up front that I understand concern about large metallic lithium and Lithium-Ion batteries on aircraft. These batteries were the source of the Dreamliner fires, and may have been implicated in certain cargo plane incidents. Metallic lithium burns without oxygen, and cannot be extinguished by water -- but no contemporary consumer batteries still use metallic lithium. Some lithium-ion batteries can overheat, melt, and even catch fire if shorted, but most are well protected from this, provided they are not crushed or damaged. Lithium-polymer batteries can overheat, but generally do not catch fire. All of these are lumped together in the rules.

In response to this, or perhaps MH 370, or I don't know what, Chinese airlines have been randomly enforcing these rules on (safe) packaged lithium-ion auxiliary batteries for cellphones and USB devices. Combine this with an utter lack of knowledge of how to convert mAh (milli-amp-hours, typically how these devices are sold) to WH (Watt-hours, which is how the rules are written), and you have a fiasco.

I was stopped and forced to move an auxiliary battery (this, in case anyone was wondering) from checked luggage to my carry-on. How this improves the safety of the plane is beyond me.

Then, on another flight, I had China Eastern confiscate this device, a combo WiFi hotspot and card-reader, which happens to also contain a small (8800mAh = 8.8Ah@5V = 44WH, well under the restrictions) battery internally. I had the instruction manual for it listing this, but they refused to let me either carry it on or check it. This was probably a case of face-saving by their idiot bureaucrats, but it meant that I lost a valuable piece of equipment.

The rules are complex, and the airline staff do not in the least understand them. I had one insist that we take apart a flashlight containing normal (non-Lithium) "AAA" cells, and pack the cells separately from the flashlight. In fact, the rules discourage "loose" batteries, which have a higher risk of a short-circuit than ones installed in devices.

I had fewer problems on the non-Chinese carriers, but not zero. Everyone had the signs out listing the restriction, something I've never seen in North America. Flights to and from China on United were no problem.

Here are some related links:

http://www.express.co.uk/news/uk/466...tery-FIRE-RISK

http://www.bbc.com/news/business-25733346

http://www.economist.com/blogs/econo...st-explains-19