Aircraft lithium battery fires

Discussion in 'Home Builders and Sport Pilots' started by Let'sgoflying!, Mar 19, 2017.

  1. wilkersk

    wilkersk Cleared for Takeoff

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    Here's what i'm wondering, in these cases of thermal runaway on Li aircraft batteries:

    (1) how many owners routinely used a "trickle charger"?
    (2) how many tried to "deep cycle" their Li battery?
    (3) how many noticed the battery was not maintaining a charge, but just continued using it, assuming the alternator would charge it up; then, they'd just plug it into the trickle charger when they get home?
    (4) how many tried to recharge an Li battery with charge of 6 volts or less?
    (5) How many put their Li battery on a charger in cold weather, cause it seemed to be weak?

    I've been carrying a lithium-ion polymer battery in my front pocket (same one) now for 3 years. It hasn't shorted out internally yet. And, I've had a couple of other cellphones with Li batteries, never had a problem (no Samsung for me! and, those were recalled anyway). ....So, my unscientific deduction is that, since all the big recalls early on, most Li aircraft battery failures that are happening now are from misuse.
     
  2. steingar

    steingar Taxi to Parking

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    Mad Cow disease is a member of a set of diseases all caused by a protein called a prion. It turns out that the prion has an abnormal conformer that is infective, it can transform normal conformers into infective ones. In humans it was first studied in the Kuru of Papua New Guinea. The disease is passed by consummation of infected tissue, the Kuru practiced ritual cannibalism. There is also a genetic from called Creutzfeldt Jakob. Two Nobel prizes have been awarded for prion research, one to a convicted pedophile.

    There was a big scare in Great Britain about ten years ago. There had been an outbreak of scrapie, which is the sheep version of prion disease (spongiform encephalopathy, if anyone is interested). Someone got the bright idea to feed the scrapie infested sheep to cows, and the infective prion jumped the species barrier. All mammals have prion proteins, but they're all a bit different. If they're similar enough consuming the tissue of one mammal can cause the disease in another.

    By the time anyone knew what was going on lots of the BSE (Bovine Spongiform Encephalopathy) cows had gone to slaughter and had entered the food chain. There were real worries that we were going to see a big outbreak of Creutzfeldt Jakob in Great Britain. Thankfully the prion didn't jump the species barrier, or they just woke up from the danger before it did.

    Were there a 1 in 20 chance of something setting my airplane on fire I wouldn't use it. But that's just me.
     
  3. Stewartb

    Stewartb Final Approach

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    Wow. Day drinking?
     
  4. zaitcev

    zaitcev En-Route

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    Since we talked about EarthX last time, they moved on; the old ETX24D and friends are no longer recommended for aviation applications, and we know now that early adopters were taking a significant risk. In my case, there was no fire, but the battery sat on a shelf for a couple of years and went into self-protection mode. When I reset and recharged it, it started self-discharging quickly - in a matter of hours. It was no longer serviceable - died while sitting under self-protection. So, I fly with the good old Odyssey PC680 again that the plane had before EarthX.

    Here's what the EarthX manual says now:

    "The ETX “Hundred Series” was specifically designed for the experimental aircraft market (models include the ETX680C, ETX680, ETX900, ETX900-VNT, ETX1200). Only the ETX “Hundred Series” battery models are recommended for use as the primary aircraft battery (starter battery). In addition to the features found in the ETZ and ETX series motorsports batteries, critical electronic circuits are redundant, the over-charge protection is enhanced, and fault indication is included. All components associated with main electronic battery disconnect are redundant. The built-in redundancy ensures that no single point failure results in the battery unintentionally disconnecting. The design aligns with the requirements for a FAA approved lithium battery as per RTCA performance specification DO-347 and DO-160. Our ETX900-VNT includes a thermal run-away containment system making it fully compliant to DO-347 specification."
     
  5. Raymo

    Raymo Pre-takeoff checklist

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    Good news, Stew. I plan to replace my PC680 at some point and lose 11+ lbs off the fwd firewall. I agree that many people lump all Lithium batteries into the same group, which causes much misunderstanding and consternation. As ChiefPilot stated, they are quite safe in a properly designed system.
     
  6. denverpilot

    denverpilot Taxi to Parking

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    That’s fascinating.

    They were doing (Wings AMT credit approved) video conferences touting their batteries not that long ago and doing some mild battery tech education for mechanics. I didn’t (obviously) need AMT credits, but I signed up for one and listened to their pitch and info carefully. I ended up thinking there were some things they might be a bit naive about, but they were headed the right direction.

    Reading that new(-er) warning, it sounds like they learned a lot, real fast, when their batteries hit the real world.

    I had not given their name a second thought since that video session quite some time ago, but I’m glad you shared that.
     
  7. Stewartb

    Stewartb Final Approach

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    EarthX is supposed to be close to FAA approval for the ETX 900. I suspect the VNT model
    is all about that. I plan to continue to test my failed battery outside of my airplane. I want to see if I can make it do something scary. So far the scariest thing it does is blink a status light. I've melted more than a couple of Odysseys so I have to say I continue to be impressed by EarthX.

    With regard to EarthX, the initial post's link has much misinformation. An ETX series battery will disconnect the battery's cells at 90% discharge. The battery can't be completely discharged and as a result can be recharged using a L-Io specific battery charger. Been there, done that, more than once. So even within the popular L-Io battery types used in Exp airplanes? Not all are created equal.

    And while there are many different chemistries used for various L-Io batteries, including Lithium Sulpher and Lithium Iron? All are classified as Lithium Ion. Many of you would benefit from listening to the archived EAA podcast about lithium batteries in exp airplanes. Learn about these batteries. They're the future.
    http://www.eaavideo.org/detail/vide...ium-batteries-explained?autoStart=true&page=5
     
    Last edited: Jul 23, 2018
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  8. Stewartb

    Stewartb Final Approach

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  9. Stewartb

    Stewartb Final Approach

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    WannFly likes this.
  10. geneseib

    geneseib Line Up and Wait

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    Reminds me of TV drug commercials and their list of possible side effects. No big deal - unless you are the one.......
     
  11. Let'sgoflying!

    Let'sgoflying! Touchdown! Greaser! PoA Supporter

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    Just want to point out, that was me quoting someone else. This site makes it possible to have it appear a person is the origination of a thought, when that is not the case. (As many sites do, nothing new there)
     
  12. Doug Reid

    Doug Reid Pre-takeoff checklist

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    I saw a nicad in thermal runaway melt through the fuselage of a turbine helicopter once. The pilot overheated the battery attempting to start the engine.
     
  13. 1RTK1

    1RTK1 Cleared for Takeoff

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    I fly Rc too, 40%ers. I’ve used many Lion batteries with no special circuitry BUT have always charge with a charger that monitors each cell, not wise to charge any other way.
    For fun one day I took an old battery and twisted the wires together, lots of smoke and fire.
    Done right “probably” no problem, done wrong an accident waiting to happen.