FAA Grounds 787s
The battery modifications such as the extra insulation between cells addresses issue 1. The stronger box addresses issue 2.
Apparently most of these events were due to excessive discharge while on a ground. When an LI battery is discharged below its minimum level it should not be recharged up to normal levels again so it is replaced. I am not an expert on this but some smart people earlier in this thread explained this. This is not a safty issue.
Last edited by peter we; 26th Mar 2013 at 21:43.
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peter we:
Comments have been made about this, and the only information I have seen is that there is undervoltage protection in the BMU at the cell level which will disconnect the battery and/or notify the BCU which will disconnect the battery.
But once that has been done, the battery is locked into this state and must be returned to Yuasa.
Based on more information since then, I suspect that part of the problem may be that the protective contactor inside the box is Normally Closed, so disconnecting the battery at that point requires constant power consumption which might take the battery from there down to the irreversible level for the cell or cells involved. Or at least requires Yuasa to evaluate its condition.
In the event of overcharge, using an NC protective contactor would be just fine.
Unless, of course, a failure inside the battery of one or more cells dropped the voltage below the operating point of the contactor.
I don't believe this. Every LI battery has protection against such possibilities because of the well known danger. A $16k battery in a critical safety situation with a revolutionary over/under charging system failed in its most basic task?
But once that has been done, the battery is locked into this state and must be returned to Yuasa.
Based on more information since then, I suspect that part of the problem may be that the protective contactor inside the box is Normally Closed, so disconnecting the battery at that point requires constant power consumption which might take the battery from there down to the irreversible level for the cell or cells involved. Or at least requires Yuasa to evaluate its condition.
In the event of overcharge, using an NC protective contactor would be just fine.
Unless, of course, a failure inside the battery of one or more cells dropped the voltage below the operating point of the contactor.
Last edited by inetdog; 26th Mar 2013 at 22:58. Reason: more at the end about overcharge....
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Neither address the problem, the cause of the failure. This is why the FAA describe the changes as 'improvements' and a not a fix, solution or answer to the problem.
http://www.gpo.gov/fdsys/pkg/FR-2007...df/E7-8186.pdf
Quoting Pax Britanica
I assume you cannot ship them because of the potentail risk involved?
So how can it be say to fly around an aircraft with two highly rated LI units bolted to the airframe, I assume I am missing something here.
I assume you cannot ship them because of the potentail risk involved?
So how can it be say to fly around an aircraft with two highly rated LI units bolted to the airframe, I assume I am missing something here.
-flammable liquids- a B744 can carry almost 170 metric tons of fuel. Try calling Fedex and telling them you want to ship 1 bottle of kerosene!
-Oxygen generators - see Valuair
-Compressed Air - Compressed gases are considered as dangerous goods, things like emergency slides, oxygen bottles and even fire extinguishers.
-Deleted uranium - used as weights (I believe 747 uses them in the stabilizers) and while safe to handle I would imagine shipping them will require them to be classed as dangerous goods.
It is possible to get exemption for extremely dangerous items to be carried.
There was a flight in the early 90s transporting a radioactive shipment from Frankfurt to the US. I was supposed to be the loadmaster on board but the permit issued only allowed 'person neccssary for the operation of the flight' so I got bumped off. The item was about the size of a largish oil-drum and weighted about 3 tons. This was a single use charter so only this item was loaded on the 747. Might not work for 787 batteries on aregular basis tho
This was an exceptional case, however lower grades of radioactive material can even be carried on passenger aircraft, here the loading height has to be observed (to have safe distance from the parcel to the roof (which is the floor of the passenger cabin).
On the freighter aircraft I worked on, there would be an Emergency Response Guide on board which gives info on how to handle different types on incidents with DGR.
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just in case anyone is wondering what the terms 'venting' and 'thermal runaway' are more commonly known as.
the PR department clearly doesn't want to use 'explosion' or 'fire' when talking about the batteries.
the action starts at 2minutes through the video
Lithium Ion Battery Explosion - YouTube
the PR department clearly doesn't want to use 'explosion' or 'fire' when talking about the batteries.
the action starts at 2minutes through the video
Lithium Ion Battery Explosion - YouTube
Last edited by s e t h; 27th Mar 2013 at 09:48.
Confusion?
Quote:
Apparently most of these events were due to excessive discharge while on a ground. When an LI battery is discharged below its minimum level it should not be recharged up to normal levels again so it is replaced. I am not an expert on this but some smart people earlier in this thread explained this. This is not a safty issue.
I don't believe this. Every LI battery has protection against such possibilities because of the well known danger. A $16k battery in a critical safety situation with a revolutionary over/under charging system failed in its most basic task?
Apparently most of these events were due to excessive discharge while on a ground. When an LI battery is discharged below its minimum level it should not be recharged up to normal levels again so it is replaced. I am not an expert on this but some smart people earlier in this thread explained this. This is not a safty issue.
I don't believe this. Every LI battery has protection against such possibilities because of the well known danger. A $16k battery in a critical safety situation with a revolutionary over/under charging system failed in its most basic task?
Where things have gone wrong (re: 150 batteries changed in service) is the operators have not really ensured that the people at the sharp end are thoroughly briefed as to the consequences of EG. Leaving the towing switch on.
The charging is not the issue (for the 150 battery swaps).
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Interesting that the Japanese seem to have a better handle on the situation than the FAA.
Accident: ANA B788 near Takamatsu on Jan 16th 2013, battery problem and burning smell on board
At the same time there is another YUSA battery problem this time on a electric car...
"TOKYO: Japanese automaker Mitsubishi Motors on Wednesday asked 4,000 owners of its hybrid and electric cars to avoid charging their vehicles pending an investigation into overheating batteries.
The move follows the melting of a lithium battery pack in a hybrid Outlander that was due for sale earlier this month, as well as a fire triggered by an overheating unit in a factory which produces the MiEV electric vehicle.
No one was injured in either incident nor was there damage to facilities.
Nearly 4,000 units of the plug-in hybrid model have been sold since its launch in January, "and we asked its owners not to charge the batteries until the cause of the incident can be confirmed," a company spokeswoman said.
The company has sold at least 68 units of its fully electric vehicle with the same battery model.
"We suspect the two cases were caused by a change in the production line of the battery supplier," the spokesman said, adding that the company had not received any similar complaints from owners of the two models.
The troubled batteries were made by a joint venture formed by Mitsubishi Motors, Mitsubishi Corp. and GS Yuasa.
GS Yuasa drew global attention over the worldwide grounding of Boeing's next generation aircraft in January after a battery on a Japan Airlines 787 caught fire and forced an ANA flight to make an emergency landing.
GS Yuasa has the contract for all Dreamliner batteries. Japanese authorities have said they had found no major problem on the company's production line making batteries for Boeing's Dreamliner."
Accident: ANA B788 near Takamatsu on Jan 16th 2013, battery problem and burning smell on board
At the same time there is another YUSA battery problem this time on a electric car...
"TOKYO: Japanese automaker Mitsubishi Motors on Wednesday asked 4,000 owners of its hybrid and electric cars to avoid charging their vehicles pending an investigation into overheating batteries.
The move follows the melting of a lithium battery pack in a hybrid Outlander that was due for sale earlier this month, as well as a fire triggered by an overheating unit in a factory which produces the MiEV electric vehicle.
No one was injured in either incident nor was there damage to facilities.
Nearly 4,000 units of the plug-in hybrid model have been sold since its launch in January, "and we asked its owners not to charge the batteries until the cause of the incident can be confirmed," a company spokeswoman said.
The company has sold at least 68 units of its fully electric vehicle with the same battery model.
"We suspect the two cases were caused by a change in the production line of the battery supplier," the spokesman said, adding that the company had not received any similar complaints from owners of the two models.
The troubled batteries were made by a joint venture formed by Mitsubishi Motors, Mitsubishi Corp. and GS Yuasa.
GS Yuasa drew global attention over the worldwide grounding of Boeing's next generation aircraft in January after a battery on a Japan Airlines 787 caught fire and forced an ANA flight to make an emergency landing.
GS Yuasa has the contract for all Dreamliner batteries. Japanese authorities have said they had found no major problem on the company's production line making batteries for Boeing's Dreamliner."
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The wire connecting the battery case to ground was broken and showed evidence of having been blown (editorial note: implicitely [sic] suggesting prior to the battery event), however, the aircraft had no history of a lightning strike.
I think this is a bit inappropriate, trying to stick it on the front-line staff at ANA and Japan AL (the two principal 787 operators so far, with more than half the total deliveries between them), and on their technical and training staff, for letting 150 batteries at USD 16k each go phut just by leaving a switch on. Remember this is a cutting-edge piece of critical kit, with every bit of software management known to engineering (supposedly) built all around it to keep it in good condition.
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Do you have loads of Ni-Cad batteries being swapped out because people leave the towing (or similar) switch on? If not why not?
In reverse order...
No, because...
1. On all other a/c, the towing switch (if fitted) does not send battery power to operate the brakes. Just lights and radio.
2. Ni-Cads, if exhausted, can be rechargd on board the a/c. (Assuming there is enough wiggly amps left to get the ground power on or a seperate battery to start the APU.) The APU battery on a 787 also supplies lights during towing on battery.
Don't get me wrong please. I lay any 'blame' if such exists, firmly at the door of Boeing for not labouring the point (IN LARGE RED LETTERS) during the initial (Boeing delivered) training courses.
It's certainly not something I remember being enforced during my course in Seattle.
Boeing train the airline trainers don't forget.
Do you have loads of Ni-Cad batteries being swapped out because people leave the towing (or similar) switch on? If not why not?
1. On all other a/c, the towing switch (if fitted) does not send battery power to operate the brakes. Just lights and radio.
2. Ni-Cads, if exhausted, can be rechargd on board the a/c. (Assuming there is enough wiggly amps left to get the ground power on or a seperate battery to start the APU.) The APU battery on a 787 also supplies lights during towing on battery.
I think this is a bit inappropriate, trying to stick it on the front-line staff at ANA and Japan AL (the two principal 787 operators so far, with more than half the total deliveries between them), and on their technical and training staff, for letting 150 batteries at USD 16k each go phut just by leaving a switch on. Remember this is a cutting-edge piece of critical kit, with every bit of software management known to engineering (supposedly) built all around it to keep it in good condition.
It's certainly not something I remember being enforced during my course in Seattle.
Boeing train the airline trainers don't forget.
Last edited by TURIN; 28th Mar 2013 at 10:04.
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Photos
@ITman good article/photos.
Are there any other photos knocking about actually showing this "Evidence of large current" as shown/mentioned in the 1st diagram in Accident: ANA B788 near Takamatsu on Jan 16th 2013, battery problem and burning smell on board - specifically between the battery contactor and the BDM?
With "high current" indications occurring before the blocking diode, it points to either an under spec'd design/components which cannot handle the design loadings, or 'something' has drawn excessive current through this area during the meltdown. I would therefore be very interested to see a before and after shot of this area / component if one exists.
The battery case earth (ground) wire looks like it may have blown similar to a fuse, so it would be nice to see if the actual battery ground wire has also suffered "high current" events as well.
Are there any other photos knocking about actually showing this "Evidence of large current" as shown/mentioned in the 1st diagram in Accident: ANA B788 near Takamatsu on Jan 16th 2013, battery problem and burning smell on board - specifically between the battery contactor and the BDM?
With "high current" indications occurring before the blocking diode, it points to either an under spec'd design/components which cannot handle the design loadings, or 'something' has drawn excessive current through this area during the meltdown. I would therefore be very interested to see a before and after shot of this area / component if one exists.
The battery case earth (ground) wire looks like it may have blown similar to a fuse, so it would be nice to see if the actual battery ground wire has also suffered "high current" events as well.
Last edited by E_S_P; 28th Mar 2013 at 11:57. Reason: being stupid !
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Thanks for clarifying that TURIN, it's been about 50 years since I did any work on Aircraft and that was a military Comet 3
Last edited by green granite; 28th Mar 2013 at 12:02.
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The third, smaller Li Ion battery, installed above the big one front of the aircraft, with small holes at the corners, that got slightly damaged according to the NTSB, will it also be re certified?
Speaking of transporting Li-Ion batteries as cargo. The bible (IATA DG) allows it, under certain circumstances, to be loaded on the main-deck of freighters. I know of one all-cargo airline who said "bollocks", and mandated all RLI and RLM be loaded lower-deck only, which is a Class C (fire suppression installed) compartment on their aircraft.
The decision was made following a very exhaustive investigation, during which a couple of packages containing Li-Ion batteries caught fire in warehouses around the world. That might have sharpened people's attention, but the decision to impose any kind of restrictions involving the carriage of Li-Ion's was met by a tremendous amount of pressure from the commercial department. Not surprising really; integrators carry an obscene amount of electronics, much of it containing batteries. The airline was actually more intent on banning the things outright, but the compromise "Class C compt. only" was made. For commercial reasons, not safety.
The decision was made following a very exhaustive investigation, during which a couple of packages containing Li-Ion batteries caught fire in warehouses around the world. That might have sharpened people's attention, but the decision to impose any kind of restrictions involving the carriage of Li-Ion's was met by a tremendous amount of pressure from the commercial department. Not surprising really; integrators carry an obscene amount of electronics, much of it containing batteries. The airline was actually more intent on banning the things outright, but the compromise "Class C compt. only" was made. For commercial reasons, not safety.
Last edited by SMT Member; 28th Mar 2013 at 18:38.
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keesje
No.
Like the Li-Ion batteries used to power the emergency lighting on the 787, A380 and A350, it's too small to be considered a dangerous risk.
The third, smaller Li Ion battery, installed above the big one front of the aircraft, with small holes at the corners, that got slightly damaged according to the NTSB, will it also be re certified?
Like the Li-Ion batteries used to power the emergency lighting on the 787, A380 and A350, it's too small to be considered a dangerous risk.
state of the art charging programm?
if a lithium battery is discharged to such a level, no re-charging should occur !
Battery chargers made for professional broadcast camera batteries diognose each battery and adjust and regulate the charging according to the health of the battery.https://www.paguk.com/sites/default/...G_Chargers.pdf
These intelligent chargers don't need seperate thermal sensors, just two wires to the battery. A micro computer uses algorythms to ensure the battery is not overcharged. The microcomputer can even sense the chemistry of the battery and can run a discharge/charge program. Each battery has a chip so the charger recognises its charging history. This kit designed to work with up to 17 volts and is available for a $1k!
What safty features designed into the Dreamliner charger?
Last edited by mickjoebill; 29th Mar 2013 at 05:33.
Nearly 4,000 units of the plug-in hybrid model have been sold since its launch in January, "and we asked its owners not to charge the batteries until the cause of the incident can be confirmed," a company spokeswoman said.
The cars had not even been shipped to customers.
Dreamliner battery maker's shares plunge | News.com.au
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I think TURIN gave the most likely explanation for this.
I wonder why state of the art technology seems not to have been employed?
What I think is happening here is the battery is designed to be allowed to discharge below it's minimum recharge value. This gives the a/c an extra few minutes of emergency power when required. The operator sacrifices the battery to ensure the whole a/c survives.