How does one define commercial aircraft
 

Some Cessna citations had A123 LFP starter (main) batteries,until one caught fire. It seems they failed to consider what happens if youconnect a 2000 amp Hobart to a fully discharged 40AH LFP battery! There gonenow do to the AD.:ugh:

It appears to be Yuasa who make the Lithium-Cobalt-Oxide cells:

Aviation | GSYuasa Lithium Power
http://www.s399157097.onlinehome.us/...06_12_2005.pdf
http://www.s399157097.onlinehome.us/...s/LVP10-65.pdf

Arent those the batteries that brought the 747 down in Dubai?

Yes Lithium batteries were the probable cause of that crash but they were in the cargo. (Not sure if the final accident report was issued?)
This incident however appears to be with batteries fitted as aircraft equipment.

With the Lithium battery's well documented ability to catch fire, one would hope that certification authorities would require them to be contained in a fire proof compartment.

These batteries will be the same "family" as Lithium-polymer.
Lithium Polymer has revolutionised the model helicopter world, a huge energy-density,massive discharge rates and rapid charging rates are some of their advantages...oh, they can be shaped to fit almost anywhere,

The down-side -charging control is absolutely critical , as is balancing of cells and a need to discontinue discharging below a critical voltage.

Failure to keep on top of things or the normal level of in-service failure of anything man-made, has caused house-fires, car -fires and other serious losses.

It is customary to recharge these model-aircraft packs in a brick/concrete bunker or a steel ex-gov't ammo-box lined with sandbags!

IMHO the technology is still too unstable for such a mission-critical application as a commercial aircraft.,,,In that situation, reliability and safety MUSt take precedence over space and weight-saving and the Lipo's heavy discharge potential.

The failure-rate IS very low, but once spontaneous combustion starts, there's NO practical way of stopping it. the offending cell/pack has to be removed to a safe area to burn itself out (like THERMITE, it doesn't need outside oxygen)

Anyone remember the spate of mobile-phone batteries getting"hot" not so long ago?....same technology. :ooh:

3 UA 787s on the ground in IAH last night and a rumour doing the rounds of the gate that the UA fleet has now been grounded. I was unable to corroborate before leaving but can anyone else confirm this?

Thank you for the link - I saw the press releases on Yuasa
 

On the Yusau site I could not find a link to the data sheetwith Co3O4 as the actual chemistry.

As an aside. I'm working with Headway LFP batteries forturbine starting. A size that fits in the 40AH RG-380 series mount. I have a proposaldrafted to use ceramic materials, for some applications as well.

Fireproof case does not solve the problems, If the casereaches 1000C it going to melt thru whatever it's sitting on. So if 50KW ofground power gets dumped into a battery it going to china syndrome no matterwhat[

LiPo vs NiCad
 

Several aircraft were lost with NiCad Runaway, most any battery including SLA can do it. The key is the charging and protection system, Gulfstream 680 has some LiFePo4 on it.

One solution is to have a low power charger for each cell and diode isolate the pack from the power buss. It is a brute force way to prevent thermal runaway of a whole pack. I think this is the Gulfstream implementation. A drawback is don’t get the real fast recharge rate the Li-Ion can provide.

Li-Po
 

It seems that they 787 may have RC copter / Cell Phone 'LiPo'. That is a brave engeering team to put LiPo in an aircraft. I guess they think if they can do Level A SW for FBW so they can Level A software to protect from battery chemistry. How about door to drop the battiers out the bottom of the plane when they get to hot!

From Wiki -

Chemistry, performance, cost, and safety characteristics vary across LIB types. Handheld electronics mostly use LIBs based on lithium cobalt oxide (LCO), which offers high energy density, but have well-known safety concerns, especially when damaged. Lithium iron phosphate (LFP), lithium manganese oxide (LMO) and lithium nickel manganese cobalt oxide (NMC) offer lower energy density, but longer lives and inherent safety. These chemistries are being widely used for electric tools, medical equipment and other roles. NMC in particular is a leading contender for automotive applications

Fox are reporting the fire as identical to "the one that caused an emergency landing in flight testing".....Laredo.

I believe the entire fleet at UA is three aircraft.

I did not know Lipo was ready for a/c, or that its character lent itself to such. The major plus is its flexibility, its ability to be shaped into panels, and structures. Not so much an energy sink.... Live and learn.....the Poly is the electrolyte, right?

Electrolyte
 

Lithium salts are always the electrolyte in a Li-Ion battery. It is what the plates (anode, cathode) are madeof that differs between types.

Has the 787 ETOPS ? if so, how does all this affect?

Just curious, retired ground person, not ever a pilot, no aptitude...
(so you vcan ignore me ...)

The 737 has ETOPS.

GT brings the elephant into the parlor.

harpf... Yes the plates, I remember the Poly represents the capability, in its flex, to incorporate a battery into a fender, a frame, or any molded structure.

The APU and main batteries are quoted as a Lithium Manganese in my 787 gen fam course notes.

I believe the FAA voice many concerns over use of Lithium Ion batteries a few years ago when they were put forward for use on the 787.

Don't know much about them as I'm more familiar with Ni-Cad types.

Lithium Manganese
 

They should be much better from a safty POV than Cobalt

ahhh... yes.. sorry

Silly me... :oh:

Not to be an alarmist, but isn't this all getting a little scary?

BTW, today's (Jan 08) JAL 787 BOS-NRT flight was sent back to the gate because of an apparent fuel leak! Not a good week for the JAL Dreamliners!

Japan Airlines Dreamliner Leaks Fuel At Logan Airport « CBS Boston

Yet another 787 problem at BOS
 

Fuel leaks from Dreamliner flight to Tokyo - Boston.com

Fuel leaks from Dreamliner flight to Tokyo; plane returning to terminal

Perhaps inadequate remediation on fuel line coupling issue(s)? The '87 sure seems to be having a lot of teething pains.

Batteries
 

The B787 main battery has a battery diode module to prevent being charged by any source apart from the main battery charger.

The APU does not have a battery module diode.

There is then a possibility that the APU battery is being over charged and any safeguards are overridden. (The APU battery is in the aft electronics bay)

So I would not be surprised if a mod came out to install a battery diode module for the APU battery.