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Lithium Ion Batteries on Aircraft

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  • #16
    Originally posted by Sunking View Post
    No it works. All you need is C4 or TNT. That should clear the fault and[B] snuff the oxygen[/B].
    [FONT=Comic Sans MS]And the crew, and the passengers....[/FONT]
    And in the case of a Lithium battery, it will disperse the components over a wide enough distance that thermal runaway is no longer possible. Not that it would matter by then.
    SunnyBoy 3000 US, 18 BP Solar 175B panels.

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    • #17
      Originally posted by inetdog View Post
      [FONT=Comic Sans MS]And the crew, and the passengers..[/FONT]
      Minor detail. Same applies to kerosene aka Jet fuel.

      On a serious note I neither condone or condemn what Boeing did. As engineers they shaved 80 pounds. FAA and NASA approved the design in 2007.

      It is kind of like this:

      Dad is the FAA
      Mom is NASA
      Daughter is Boeing
      I the public passenger was entitled to screw you daughter.
      So who are you going to Blame?
      MSEE, PE

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      • #18
        Originally posted by Naptown View Post
        [FONT=Comic Sans MS]I guess the same technique for extinguishing oil well fires would not be appropriate?[/FONT]
        The operation was a success - unfortunately the patient died
        [SIGPIC][/SIGPIC]

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        • #19
          Originally posted by Sunking View Post
          Doubtful they would work because LFP ha squite a bit of internal resistance. That is one reason the aircraft industry NiCd and AGM to get the very high current to run the starters on jet engines.
          Jet engines on airliners don't use starters. Batteries are used to start small auxiliary power units; compressed air from the APU's then start the engines.

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          • #20
            Originally posted by AzSun View Post
            Retrofitting to traditional technologies will be expensive. While not a problem yet, I hope the aluminum wiring that was also selected for this aircraft doesn't become one some day. I seem to remember is was discontinued for use in mobile homes years ago due to fires. So let's throw it on an airplane. This will all get fixed but what an example of penny wise and pound foolish.
            The first pressurized aircraft were well known for breaking up in flight when repeated pressurization cycles caused metal fatigue. That did not result in them giving up on pressurization; it resulted in better designs (stress relief, crack propagation prevention features) that allowed aircraft to handle the repetitive stresses of pressurization.

            We'll follow the same path here. This isn't even one of the bigger efforts to minimize weight; things like carbon fiber construction, fly by wire design, 5000psi hydraulics, glass cockpits etc have all contributed to lower weight/higher performance/lower operating cost aircraft. All those improvements had their share of disasters, but we worked through all of them. We're seeing the same sort of growing pains here.

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            • #21
              Originally posted by Sunking View Post
              Doubtful they would work because LFP ha squite a bit of internal resistance. That is one reason the aircraft industry NiCd and AGM to get the very high current to run the starters on jet engines in addition they do not spill. Cobalt has low internal resistance and very high energy density. That is why Laptop Manufactures prefer to use Cobalt over LFP.
              Have you seen the specs on higher end LFP batteries like A123 (yeah, the company went bk - based on management ineptitude, not chemistry).
              Good LiFEPO4 has high power. They use A123s in Drag racing motorcycles, had used in Formula-1 applications, a small set in BMW hybrid cars, forthcoming Chevy Spark EV, the Fisker Karma. They should provide well enough power to start the engines. I don't believe the box that Boeing showed was the battery that started the engines - was that true? I know that dump rates on some LiPoly is very high but A123 are quite close to that. And, you can drive a nail through them, dead short them, no venting with flame.
              PowerOne 3.6 x 2, 32 SolarWorld 255W mono

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              • #22
                Originally posted by bonaire View Post
                Have you seen the specs on higher end LFP batteries like A123 (yeah, the company went bk - based on management ineptitude, not chemistry).
                Good LiFEPO4 has high power. They use A123s in Drag racing motorcycles, had used in Formula-1 applications, a small set in BMW hybrid cars, forthcoming Chevy Spark EV, the Fisker Karma. They should provide well enough power to start the engines. I don't believe the box that Boeing showed was the battery that started the engines - was that true? I know that dump rates on some LiPoly is very high but A123 are quite close to that. And, you can drive a nail through them, dead short them, no venting with flame.
                One of the batteries is the last ditch backup source for all the critical electrical flight controls. (The 787 does not use mechanical or hydraulic as much as previous planes). The other is the starting battery for the APU, not for the regular engines. And even then it does not have to be used if other power sources, like the main engines or a shore connection, are available for starting.
                SunnyBoy 3000 US, 18 BP Solar 175B panels.

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                • #23
                  Originally posted by bonaire View Post
                  Have you seen the specs on higher end LFP batteries like A123 (yeah, the company went bk - based on management ineptitude, not chemistry).
                  Boeing used Cobalt, not LFP.
                  MSEE, PE

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                  • #24
                    Originally posted by inetdog View Post
                    But in the case of a Lithium battery fire, the "electrical" fire will also keep going after you disconnect the battery.
                    Unless you piss on it a lot. (See the FAA guidelines on fighting a Lithium battery fire.)
                    HAHAHA each 787 needs to carry 3 elephants just in case they need to piss on the batteries!!!!!!

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                    • #25
                      Originally posted by Sunking View Post
                      No it works. All you need is C4 or TNT. That should clear the fault and snuff the oxygen.
                      hopefully after the battery is plunging to Earth after being ejected!!!

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                      • #26
                        There are severe safety issues with the current lithium-ion batteries that are used in electric and hybrid vehicles. However, a research firm states that it has found a way to make a better battery that can create a longer driving range by utilizing a solid electrolyte rather than a liquid one. Article resource: Improving electrolytes for lithium-ion batteries.

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                        • #27
                          Everybody and their brother has a new and improved electrolyte formula, from salt to moon-dust.

                          Actually bringing them to market beyond the funding stage, or battling through patent-litigation issues are the major holdbacks. And if they do succeed, much of it may end out of the hands of the common man, and wrapped in a proprietary or oem-use only agreement.

                          While we're waiting for nirvana, Lifepo4, that is quality lifepo4 and not DIY junk counterfeits and rejects, already fulfills the safety and power need.

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