More Scrutiny Of Lithium Batteries On Aircraft

[FlyingPhotog]

NY Times ARTICLE (http://www.nytimes.com/2009/10/27/business/27fires.html?_r=2)

[e02937]

Interesting article

[mikekelley]

The TSA site says that it is still okay as long as you protect the terminals. So just cover the terminals with gaff tape if you're going to carry spares...it also says that batteries are okay installed in devices, but that loose batteries are the issue. So just cover the terminals with gaff tape and you are good (that is what I got from it)

[pwm2]

The rules are quite nice, when put in relation to the amount of energy. Basically max 3 laptop batteries and no Lithium-based UPS battery. Weight/volume to limit camera batteries in the carry-on.

[Thalagyrt]

Speaking of the TSA... This actually got a response from them: http://xkcd.com/651/

http://www.tsa.gov/blog/2009/10/response-to-bag-check-cartoon.html

[Picture North Carolina]

Thanks for sharing the info. Good to know.

[mikekelley]

Speaking of the TSA... This actually got a response from them: http://xkcd.com/651/

http://www.tsa.gov/blog/2009/10/response-to-bag-check-cartoon.html


:lol::lol:

[DeaconG]

And my family wonders why I refuse to fly on aircraft anymore. These days, it's Air Infiniti or it ain't happening...

[nphsbuckeye]

Oh well, in a few years I'll have my own jet. :lol:

[JWright]

I wonder if the problems with batteries stems from the numbers of batteries purchased from places like ebay because users want to save some money. I imagine a lot of ebay batteries are manufactured in places like China, Indonesia or Maylasia with little or no quality control...

[pwm2]

I wonder if the problems with batteries stems from the numbers of batteries purchased from places like ebay because users want to save some money. I imagine a lot of ebay batteries are manufactured in places like China, Indonesia or Maylasia with little or no quality control...
Not likely, given the battery call-backs of big-brand batteries.

A battery contains a lot of energy. And the goal is to increase the amount of energy per weight unit to get lighter products and/or longer battery times. To get light batteries, you can't make the batteries too robust. A mechanical damage can get the battery to fail critically.

The next thing is that we want fast charge times, so all modern battery chargers are fast chargers. But lithium-ion batteries must not be over-charged. As soon as the battery is full, the energy will no longer be converted from electrical to chemical form. It will instead be converted to heat. And a charger capable of fast-charging a big battery is also able to very quickly rise the temperature of the battery. The solution to fast-charging is to have a smart chip in the battery, and to switch from fast to slow charging when the battery is nearly full. But we want fast chargers, so we get unhappy if the documentation says 1 hour 30 min charging instead of 1 hour charging. Some companies have found a reasonable work-around. They fast-charge to 90% and document that battery level as full. Then they specify a bonus capacity - if the user is allowing 30min or maybe an hour, their smart charger will allow the battery to be filled to 110%.

Earlier camera generations used först NiCd and then NiMH batteries. They are very stable technologies. But the lithium in todays batteries is so very, very reactive. It is this reactivity that gives the large energy capacity. But also giving the problems that even small design errors or accidents or overcharging almost directly changes the battery from nice and stable into a fire hazard or small bomb.

It is enough that a small variance in any production parameter for creating a battery that is slightly different. Still perfect quality, but suddenly one of the carefully selected parameters for charging the battery isn't valid anymore, resulting in a good-quality charger overcharging a good-quality battery.

Life doesn't get better when we buy knock off copies of batteries and chargers. The quality of the copies may be excellent. But the variance from just having the chemistry produced in a different factory may be enough to change the behaviour of the produced batteries enough that much of the originally planned safety margin has been lost.

Next thing is that lithium-ion batteries ages from the day they were produced. The total capacity will decrease even if the batteries are not used. If the battery has been on a shelf for a long time since the last charge, the ageing may have decreased the capacity so much that the computed time to speed-charge the battery may be wrong. A good quality battery and good quality charger. But the incorrect assumption about total capacity in the battery may lead to the battery getting overcharged.

So in the end, I don't think we have any real problem with the quality of the knock-off batteries. But we have a problem in that we expect much. Sometimes just a little bit more than what is safe.