back to article Boeing outlines fix for 787 batteries

Boeing has outlined plans to improve the performance and safety features of the batteries used in its 787 aircraft, after two of the planes infamously experienced on-board incidents at Takamatsu and Boston, but has stopped short of offering a thorough explanation for just what went wrong. What is known is that something caused …


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  1. Esskay

    If only Lucas had this PR team

    Then the electrics on my mini could be said to perform a "safety venting procedure" every time I triy to use the headlights and the wipers when it starts raining.

    1. TheVogon

      Re: If only Lucas had this PR team

      Should have bought an Airbus....

    2. Anonymous Coward
      Anonymous Coward

      Ladies and Gentlemen

      Ladies and Gentlemen, we have good news and bad news

      The good news is we will be landing early

      The bad new is we are going to craaaaaaaaaaaash!

    3. Anonymous Coward
      Anonymous Coward

      Remind me to wait

      Remind me to wait a few years before I fly in any newly designed cutting edge aircraft.

      I think 10 years would be sufficient for all the recalls and problems to be sorted out and the lessons learned from 3 or 4 crashes to have been put in place.

    4. JCitizen

      Re: If only Lucas had this PR team could be total fail!

      The problem is that Boeing's stupid engineers are trying to force their design contractors to put a compact battery design in a plane, when everyone in the battery market knows full well, that you can't get away with such a design without heat overun! Every EV maker realized this, but the junior gee-man execs at Boeing will not admit it. They better wake up before the FAA grounds them permanently for such stupid decisions. You gotta wonder just what is going on in that company - that used to have such good sense, and allowed so many of us to fly so safely, that they refuse to see what is in front of there faces and risk the safety of the flying public?!! What happened to good 'ol Boeing safety sense? Stupid top executives?

      It make me wonder what other bad decisions they are making on modern composite superstructure?! The mighty fall hard, but not with my butt flying on it!

      If I were a stock holder, I'd wonder!

  2. Yet Another Anonymous coward Silver badge


    Not an explosion - just a "prompt exothermic disassembly"

    1. Anonymous Coward
      Anonymous Coward

      Re: Hindenberg

      So it vented, but so did the Hindenburg.

      It still caused the surrounding area to be damaged, and if this had happened in flight would the aircraft have arrived with a hole in the wing?

      1. SkippyBing

        Re: Hindenberg

        No, because the battery is in the fuselage. How bad a hole in the fuselage is depends on which side of the pressure bulkhead it is.

    2. Doug Bostrom

      Re: Hindenberg

      Years ago I was the lucky person with our firm who took the (Christmas week) phone call announcing that a device which we'd just installed had exploded and reduced itself to small fragments and a cloud of black smoke in a shopping mall in the NE US, prompting an evacuation and demand that we immediately remove the approximately 1,800 other copies deployed around the mall's local community (this was in 2001 and in general emergency responders were quite jumpy, to say the least).

      Reversing this setback was quite an education. Although their battery had exploded for a reason that was never satisfactorily explained, luckily our vendor (a very large French battery firm) appeared well-versed in the art of euphemisms as they apply to badly behaving batteries. We were instructed to never use the words "explode" or "detonate" or "burst" in the technical reports demanded of us by regulatory authorities; the proper words to use were "spontaneous disassembly."

      And lo, the magic words worked. We never removed a single device. :-)

    3. Stuart21551

      Re: Hindenberg

      No, the whole problem was faulty smoke detectors incorrectly detecting the non smoke.


  3. Ragequit

    I put my money on...

    Boeing overcharging the batteries because if they could blame the other guys they would do so. Re-certifying the system is a major time and money sink. By not pointing fingers and acting in concert with the parties involved to provide a solution to a problem they're unwilling or not able to describe.... they smell guilty. Either the whole system was truly under designed or outsourced code wasn't tested as much as much as it should due to a lower criticality.

    Aerospace industry politics as usual I guess?

    1. collinsl Bronze badge

      Re: I put my money on...

      As the incidents happened on the ground it would appear that overdrawing is the problem, not overcharging. A plane's batteries are recharged in-flight by power from the engines. On the ground the batteries are used to power cockpit equipment whilst the plane's engines are not running. Normally on the ground the APU (Auxiliary power unit) is running to provide in-cabin lighting, seat power, AVOD (Audio Visual On Demand) equipment & galley power (etc) and power to the cockpit equipment. Starting the APU draws power from the batteries, much like a car engine. Bleed air from the APU is used to start the main engines as hot air is needed.

      In the case of the 787 Boeing, in their infinite wisdom, appear to have thought something like this: "Wow, we have this really cool new battery technology that gives us more power for longer. We use the APU for power on the ground but this uses expensive jet fuel. Why not transfer some of the load from the APU to the batteries whilst on the ground? This is SO COOL!" This is a good idea, but they appear to have the current requirements too close to the endurance limit of the batteries.

      1. MondoMan

        Re: collinsl

        The Japanese incident happened in mid-flight, prompting an emergency landing.

        1. Anonymous Coward
          Anonymous Coward

          Re: MondoMan

          Yes. but in an electrical system batteries can also act as electrical accumulator and given that Boeing also refer to the 787 as the plastic electric[1] 'plane so collinsls explanations is still plausible.

          The traditional method of charging batteries is to constantly pass current trough them so it is not inconceivable that rapid charge/discharge cycles would cause a cell/battery to overheat.

          [1] If you ever get close enough to a 787, i.e. the wing rear spar and the wheel wells, you will notice that there are a lot less hydraulic lines and cables and a lot more electrical harnesses than there are on 'older' aircraft.

    2. MondoMan

      Re: I put my money on...

      The battery design and production and the battery charging system design and production were all outsourced; the former to Yuasa and the latter to Thales. The Thales group working on the charger infamously had their whole building burn down due to a single battery catching fire/////////////experiencing thermal runaway////////whatever during early charger testing some years back. After that, their further charger testing did not use actual batteries, but rather simulated battery load devices that could not burn down the building.

      The recent investigations revealed that the final charger design had never actually been fully tested with actual batteries instead of simulated loads.

    3. auburnman

      Re: I put my money on...

      I don't think Boeing would point the finger at anyone else whether or not they can. Right now they will be mega focussed on trying to twist the facts to their world-view where "no fire occurred" and the 'smoke' was a planned safety release. They need everyone to believe this message so they can recertify the planes and get them back in the air before the airlines start cancelling orders/demanding refunds/suing.

  4. simon 43

    So they describe the non-fire as thermal runaway and the add extra insulation around the cells and enclose it all in a box....

    Note too the technical fix of 'wrap the cell in insulation (electrical) tape - sounds like they got Jim the 'leccy in for that one!

    I really hope that this does sort the problem, new ways of doing old things (Apple innovations) often have teething trouble, and so far no one has been seriously injured - long may that continue!

    1. simon 43

      D'oh, its not described as thermal runaway... just a build up of heat and pressure in one cell which vented and caused another to build up heat and pressure which vented and...

      Still not sure of the wisdom of giving these cells an overcoat!

      - Reg, we need an edit button!

    2. collinsl Bronze badge

      Insulation is necessary to prevent the batteries freezing at -53 degrees C (or colder) whilst in flight.

      The electrical tape is there to attempt to prevent thermal runaway by insulating each cell against the others (obviously this didn't work).

      1. MondoMan

        Re: insulation/electrical tape

        Not sure if the electrical compartment is fully climate-controlled, but it doesn't get down to -53C, nor even below freezing IIRC.

        The battery cells were already in a metal box; the new metal box will be stronger, and the individual battery cells inside will be separated by thermal insulation so that even if one cell experiences thermal runaway, not enough heat would be transferred to any adjacent cell to trigger its thermal runaway.

        In the current design, all the cells were packed together, as it was thought that any one cell could not induce an adjacent cell to overheat (wrong!). Apparently, there were not even individual voltage/current monitors on the cells, just on the whole

        1. Red Bren

          Re: insulation/electrical tape

          "The individual cells inside will be hidden by thermal insulation so that even if one cell experiences A PERFECTLY NORMAL AND SAFE EVENT, no one will notice and criticise our planes again!"

          Fixed it for you.

        2. ilmari

          Re: insulation/electrical tape

          Individual voltage monitors per cell is an absolute must!! Without that capability, the cells WILL drift apart over time, and one cell will get overdischarged or overcharged.

          NiMH, NiCd and Pb batteries tolerate overcharge (within reason), so those packs ae always slightly overcharged, to ensure that the individual cells stay balanced. LiIon has zero tolerance for both overcharge and overdischarge. When charging, individual cells must all be monitored, if a cell reaches max voltage beforr others, the battery management system must tell the charger to slow down, and also start draining power away from that cell.

          Without this, the batterypack is a ticking timebomb.

          1. Tim Jenkins

            Re: insulation/electrical tape

            "the batterypack is a ticking timebomb"

            I'm imagining more of a bubbling, fizzing kind of sound, possibly followed by a pop/hiss kind of thing...

            1. Anonymous Coward
              Anonymous Coward

              Re: insulation/electrical tape

              The battery holds 60Kw/hr of energy which is all released, it about 6.5litres of petrol.

              In the 90 minutes the fire department tried to put out the fire it would have averaged 40KWatts

  5. M7S

    The vaporised electrolyte was jettisoned overboard, so never posed a risk to passengers or crew

    A bit of a sod though for anyone on the ground suddenly getting a faceful of battery acid

    1. Dave Pickles

      Re: The vaporised electrolyte was jettisoned overboard, so never posed a risk to passengers or crew

      Except that in the Boston incident, the failure of the battery caused the APU to stop (because the APU control unit is directly powered from the battery bus). This removed power from the fans intended to ventilate the equipment bay and keep fumes out of the cabin.

      1. Anonymous Coward
        Anonymous Coward

        Re: The vaporised electrolyte was jettisoned overboard, so never posed a risk to passengers or crew

        The APU battery also controls the fire extinguishers for the APU, so no battery no APU.

        The APU is integral to ETOPS, so no APU, no ETOPS and no economic reason to buy the 787.

        1. Anonymous Coward
          Anonymous Coward

          " no APU, no ETOPS and no economic reason to buy the 787."

          " no APU, no ETOPS and no economic reason to buy the 787."

          I know what that means, as I suspect do most folk that understand what ETOPS means. Most of them (except Boeing spinners) probably agree with it too.

          I don't understand the detail well enough to write a brief explanation of it here for someone who doesn't know what ETOPS means. Is the Wikipedia ETOPS article appropriate as a starter?

          1. Magani
            Thumb Up

            Re: " no APU, no ETOPS and no economic reason to buy the 787."

            @AC 130317 17:39

            "Is the Wikipedia ETOPS article appropriate as a starter?"

            It lacks a lot of references, but as a primer it's OK.

          2. Anonymous Coward
            Anonymous Coward

            Re: " no APU, no ETOPS and no economic reason to buy the 787."

            ETOPS is simply the distance away from the nearest airport an aircraft can fly. The 777 took about a decade to prove it could fly 240minutes from a airport (over sea, siberia etc).

            Boeing attempted to have the 787 approved for ETOPS 330 at launch (5.5 hours flying time on one engine). This in an aircraft that has "revolutionary" (aka experimental) electrical systems and carbon fiber body work that has never been tried before.

            The 787 has been plague by many issues since launch (faulty undercarriage, fuel leaks, hundreds of battery failures etc), yet the Boeing management will demand its given ETOPS due to its incredible reliability record.

  6. Anonymous Coward
    Anonymous Coward

    Being an AC I think I am also make a C as I don't think I will fly on one of these jets until they have had a bit more flying time!

    *dons foil hat*

    1. Anonymous Coward
      Anonymous Coward

      Wow my grammar is amazing today. Take 2...

      I think I am definitely a C as I don't think I will fly on one of these jets until they have had a bit more flying time!

      *dons a second foil hat*

  7. Great Bu

    'losing batter power'

    ....with terrible consequences for the on-board fish 'n' chips shop......

  8. Yag

    Can't figure it out...

    Is it a description of the 787's battery issues, or of the fukushima disaster?

  9. Zmodem

    I said it is obviously heat transfer in the comments for the other article with photos of the batteries

  10. Graham Marsden


    ... actually it was just the Magic Blue Smoke (that all electronic equipment has inside) escaping...

    1. Solmyr ibn Wali Barad

      Re: So...

      Either that, or zillions of tiny lightnings decided to group together, and form an all-too-powerful chain lightning.

      Yes, there are only precious few, who are able to tame such a force.

      Even your humble servant has grown lazy over the aeons. Now I'm quite content to spend my days herding the tiny lightnings around their green pastures. Not to mention that people do not object so much.

      But sometimes I miss the old days. Great flashes turning nights into days, mighty roars shaking the ground, and of course, that unforgettable smell of the fresh ozone... Ahh.

      /mine's the one resembling a Faraday cage/

  11. Anonymous South African Coward Bronze badge

    Gonna be ironic if the new batteries promptly overheat and vent with all the execs on board, high up in the sky...

  12. Magani

    Talk about a load of PR spin.

    The statement was just a 'Don't you worry about it - we know what we're doing' pat on the head to the authorities. I hope the FAA have the cojones to stand up to this blithering and see it for what it is - a bandaid solution to a problem that Boeing has admitted not knowing the cause of.

    Fire (sorry, shouldn't use the F word) is the ultimate no-no on board an aircraft. Building a big strong box around something that Boeing said could never catch fire in the first place is not an elegant solution.

    If these things get recertified, I will not be wanting to experience their 330 minutes ETOPS certification capability in the next few years. I'd rather stick with either a 380 or 777 or ever a 747 for my long haul jaunts.

    Note that the icon does not represent fire.

  13. James Micallef Silver badge


    " A manufacturing fault seems to be the reason such an event was able to occur "

    Clearly this is not true since (a) it happened on 2 separate planes, so manufacturing must have been REALLY shitty (b) they are doing design changes to solve teh problem, so it was a design fault in teh first place

    1. MondoMan

      Re: Bollocks

      James, in fact dozens (maybe hundreds) of batteries have had to be replaced on 787s (albeit not all due to self-failure), so something was already known to be going on.

      The concern is in fact that manufacturing QC standards were way too low at Yuasa's plant. After the incidents, an advisory group that included folks from the automotive lithium battery sector visited the Yuasa plant and was reportedly shocked that 80% or more of their cells were passing muster, as in the automotive lithium battery plants typical pass rates were closer to 60%.

      Maybe Yuasa's plant is that much better than everyone else's, or maybe not.

      1. Anonymous Coward
        Anonymous Coward

        Re: Bollocks

        No manufacturing faults have been found in the 100+ failed batteries. That just another lie from Boeing as nobody can disprove it.

        Boeing attitude to safety in shocking, as is their logic. E.g. Only a overcharging event can cause a fire, there was no overcharging therefore there was no fire.

      2. James Micallef Silver badge

        Re: Bollocks

        @Mondoman, thanks for the additional info, didn't know they had lots of other batteries replaced. Nevertheless, if it was ONLY a manufacturing issue, surely they would just insist that Yuasa ups their standards. If they need a redesign, that means the original design wasn't good enough (even if the redesign is only to improve the manufacturing process)

        And I hope Yuasa's Pb batteries don't explode, my 'bike has a Yuasa battery, and it's located right under my ball!

  14. Anonymous Coward
    Anonymous Coward

    Using a battery that is very unstable at high temps was a pretty bad idea. While any batteries have problem, lithium ion batteries tend to go crazy after a certain temperature.

    Give me hydraulics any day.

  15. Field Marshal Von Krakenfart
    Paris Hilton

    The Paris school of enginerring

    a “deep discharge” event occurred in one cell of the planes' batteries, heating it to the point at which it vented so much hot electrolyte that an adjacent cell warmed and also vented.

    Fnarr Fnarr.

  16. Schultz

    Stupid japanese pilots...

    can't distinguish evaporated electrolytes from smoke or a thermal runaway process from fire. Clearly nothing to see here ...

  17. Anonymous Coward
    Anonymous Coward

    (1) "Venting" (2) Lucas

    (1) Who can provide a link to the photos of the batteries and enclosures post-"venting"? I've seen some of them, and it sure looks like more than the venting as described by the Boeing PR spin regurgitated here. The pictures are probably in the PDFs of the official reports, if they're not elsewhere.

    (2) Q: Who knows who's been building the safety critical bits of Rolls Royce's aero engine fuel systems (pumps, computers, software, etc) for the last few decades?

    A: Lucas. Specifically, Lucas Aerospace and some of its successors, ending up as a company called Aero Engine Controls. As of last year, Rolls Royce own 100% of Aero Engine Controls. Not saying whether this is good or bad (time will tell).

  18. Tomas K.

    Seems plausible

    Maybe this investigation will prove beneficial to all who employ lithium-ion batteries?

    1. Yet Another Anonymous coward Silver badge

      Re: Seems plausible

      Yes, we no longer have to worry about them exploding

      Now that we know they only ever safely vent the corrosive contents into your face - for their own safety

  19. Captain DaFt

    Amazing fix

    So their two pronged strategy to correct the problem is:

    1. Make sure there's nothing insulating the cells to prevent heat build-up,

    2. Insulate the cells to prevent one overheating from affecting the others.

    Umm... Yeah...

    1. Zmodem

      Re: Amazing fix

      just use toughened plastic or another low heat conduction material for the housing of battery cells.

      4 batteries running at "25c" with metal housing, and eventually all batteries could have a operating temperature of 100c if charging them up is not controlled properly

  20. JaitcH

    Now we need a new interpreter for this high tech gobbledigook

    "has stopped short of offering a thorough explanation for just what went wrong" means they haven't a clue.

    "something caused the batteries on two 787s to become very hot" is stating the obvious given there was smoke, flames and heat.

    "deep discharge” could be a short circuit - they are known to cause 'deep discharges'.

    "the venting is a protective measure" means it reduces the chance of a battery acting like a BOMB.

    "heat from the cell propagated to other cells and they vented as well. This is a protective mechanism that is designed into the battery cells" now we have unionised batteries - one on fire, now all on fire.

    "they leak vaporised electrolyte which looks like smoke" sure, now explain the flames, acrid smoke and scorching.

    "systems worked as planned with flight crews notified after smoke detectors worked" is such a stupid statement - why sound the alarm before an alarm condition is reached?

    "cannot be considered a “thermal runaway” so just what the hell is all this fire and heat if it isn't runaway? Or did Boeing plan for fires?

    For a high tech aircraft manufacturer who expects passengers to entrust their lives to their plastic plane we also expect far more cogent answers than the rubbish muttered the other day.

    (Today's NSA word is Acritic. It keeps their computers buzzing, and increases readership)

    1. ChaosFreak

      Re: Now we need a new interpreter for this high tech gobbledigook

      Where have you seen a source that confirms there was flames? I saw some photos of melted batteries but you don't necessarily need open flame for that. Just interested...

  21. fgrieu

    Is "Deep discharge" mentioned in the video?

    Is "Deep discharge" mentioned in the video linked with the article? If yes, approximately at which offset please? Listened to most of it, could not find it.

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