DreamLiner and Li-ion

[Dave Plowman (News)]

So they've just discovered Li-ion can be a fire risk?

[Mike Tomlinson]

En el artículo , Dave Plowman (News) escribió:

Seen the photos of the batteries?

't be too happy flying with that happening under my feet.

[Martin Brown]

Not really surprising. Li-ion is volatile chemistry and if it gets slightly maltreated can go into thermal runaway self heating. That is the price for the energy density vs weight trade-off.

The big worry is that on the Dreamliner the electrical systems are absolutely essential for control of the flight surfaces. There is no independent hydraulic system although presumable there must be some manual way of lowering the undercarriage for landing in extremis.

[Dave Liquorice]

They've know about it for a long time. Have a google for the restrictions put on Li technology batteries in baggage/freight...

Seems like a major cockup to use Li technology batteries as part of an aircraft without taking some very careful measures to ensure they won't catch fire. The big problem with Li batteries is that they contain their own oxygen, so are self sustaining. Fire supression systems that rely on removing/reducing the available oxygen, inert gas, foam, dry powder, etc don't work.

[Brian Gaff]

Oh really, well any battery with the kind of current capabilities can be a fire risk. I just wonder if they enclose them in flame retardant and explosion proof containers. this apparently is the case with manned space flight devices, though I'm not sure about the laptops on the ISS, certainly the sat phone used in the soyuz has the battery protected this way. Brian

[Dave Plowman (News)]

It can be if it is shorted, etc. But lithium types appear to be capable of being this on their own.

[Jo Stein]

I would be quite happy with that. The chance of dying in a plane is far less likely then dying in your home:

LOSS OF LIFE EXPECTANCY (LLE) DUE TO VARIOUS RISKS

...

...

[polygonum]

Whilst we have reasonable statistics to reassure re the general safety of flying, I feel that we do not yet have sufficient knowledge of the safety of Dreamliner 787s. Only in service since October 2011. So anything that takes a couple of years to surface...

BTW, how long do lappie batteries typically last? Seem to remember they start failing in their second year and often get worse over the next two or three years.

[Nightjar]

Possibly not. The undercarriage is only really essential if you want to be able to take off again after the landing.

Colin Bignell

[Davey]

=46rom a report of the earlier incident: "In today=E2=80=99s problem, the automated landing gear did not operate, but the pilot was able to lower the landing gear manually =E2=80=93 using gravi= ty =E2=80=93 and landed on the plane's second approach to the runway."

kind-of, sort-of, maybe. As long as the undercarriage doors open.

--=20 Davey.

[Nightjar]

That does rather depend upon the aircraft.

Colin Bignell

[John Williamson]

Some laptop suppliers had to recall a lot of batteries a while ago....

Didn't some Apples burst into flames?

[Jo Stein]

Why do people clap their hands after a landing? Because we are afraid of heights. Why are we afraid of heights? Because of evolution, which also explains why goats are not at all afraid of heights.

I will prefer an Airbus A350 when flying long distance, and my choice is not based on irrational fear:

[polygonum]

Or the passengers want their luggage not strewn across the, I was going to say "runway", but maybe "wherever they happen to land".

[polygonum]

And started recruiting people who might know something:

Electronic / Electrical Test Engineer (Lithium, Battery)

Electronic / Electrical Test Engineer (Lithium Batteries)

Oxfordshire

To £27k - £32k + benefits

An excellent opportunity has arisen for an experienced Battery Test Engineer to join a rapidly expanding technology company specializing in the Design and Manufacture of Next Generation Lithium Battery technology. The ideal candidate will be a Test Engineer with both the technical and theoretical knowledge to provide a battery testing service within the R&D group working with minimum supervision and providing technical competency in lithium based cells or batteries testing and quality assurance using internal or external facilities. An experienced candidate is preferred however an outstanding individual with an excellent understanding of the basic electronic / electrical principles' would be considered.

Key areas of test duties

• Cell testing to the Test department specifications on prototype Li-S cells.

• Cell processing and quality assurance of Li-S cells manufactured for customer battery projects.

• Testing products to customer specifications and in accordance with Test department quality specifications.

• Timely delivery to the customer ensuring that all batteries are built and tested ahead of the dispatch date.

Main duties:

- Electrical verification by checking the voltage of cells etc

- Test harnesses design and production

- Safety handling of lithium based cells and batteries

- Document writing - SOPS, reports etc

- Data gathering and analysing

- Basic Quality assurance

- Developing test plans and strategies

- Use of Maccor cells and batteries electrical cycling test equipment

- Technical support to the R&D team

- Safety tests on Li-S cells and batteries (nail penetration, short circuit, overcharge test, thermal stability test)

- Bonding and isolation tests

- Destructive parts analysis on Li-S cells in a dry room

- Supporting the maintenance of internal Test facilities and test equipment

- Developing test equipment and procedures

Main skills:

- Basic practical electrical/electronic knowledge (Ohm's law, Kirchhoff's laws etc)

- Battery or cell electrical and mechanical testing (preferably lithium based batteries)

- Ability to use Maccor cyclers

- Able to work with mechanical and electrical drawings

- Knowledge of working with testing equipment: DVMs, PSUs etc

- Excel and Word basic principles

- Basic soldering skills

- Thermal cycling of a battery products

Education: HNC/HND/BTEC in Electrical/Electronic Engineering + experience in Li based cell and battery testing

:-)

[Tim Streater]

Only during testing/development. Not that that stopped the Windows fanbois making much of it.

[tim.....]

Apparently, these batteries are not used to "fly" the plane (presumably that is done using electricity generated by the engines somehow)

They are only used for power when the plane is on the ground

[Tim+]

More relevant though is how often do they burst into flames? Yes, it has happened but when you consider the millions of batteries that must have been produced it seems as if they've "tamed the beast" and made them acceptably safe.

Tim

[polygonum]

Suspect that they get recharged (if needed) in flight. So they might not need to provide power in the air but, one imagines, could as easily take up smoking in flight as on the ground.

[Dave Plowman (News)]

The battery in your car doesn't do much when the car is running - but that doesn't make it unimportant.