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Ian W:
I'm going to look b awkward again, but laptop batteries are rechargeable and use a different chemistry. We all know some laptop batteries have had issues, but it's not really relevant to this thread. Ancient Mariner's post (thanks) triggered memories from years ago about the volatility and safety of early lithium batteries, primary non rechargeable types, but haven't heard any reports for years in that respect. My guess is that the unsafe chemistries from years ago are no longer used. The cells used in the elt are lithium manganese, nothing like the lithium ion types used in laptops. The lithium managanese types are also the most common chemistry used for consumer products, lithium coin cells etc, which are well proven and safe. Good overview in a Wikipedia article here: Lithium battery - Wikipedia, the free encyclopedia |
For the umpteenth time !
and in a sealed environment, there wouldn't be enough oxygen to sustain a fire long enough (if one even started inside the ELT), that would burn through the enclosure. ELT batteries are NOT chargeable ELT is not normally connected to Aircraft electrical system- note I said NORMALLY - but ' sneak" circuits due to poor grounding, flaky connections, crossed wires, etc ** could ** possibly exist. Battery protection diodes can fail for example internally, etc. LI-x fires can be like a cutting torch. Model airplane LI-x batteries can and do catch fire if abused/shorted/etc but they ARE rechargeable. :* |
. My guess is that the unsafe chemistries from years ago are no longer used. |
LI -x batteries do NOT need Oxygen to continue to flame- the chemistry is such they generate thier OWN oxygen. ELT batteries are NOT chargeable ELT is not normally connected to Aircraft electrical system- note I said NORMALLY - but ' sneak" circuits due to poor grounding, flaky connections, crossed wires, etc ** could ** possibly exist. Battery protection diodes can fail for example internally, etc. LI-x fires can be like a cutting torch. Model airplane LI-x batteries can and do catch fire if abused/shorted/etc but they ARE rechargeable. |
Environmental conditions can be critical
Ancient Mariner showed photos (many thanks) and said:
[The batteries were taken straight out of the box and put on shelves, they were airfreighted! to us and we could not find anything wrong with the boxes. ] i wonder if the reduced pressure environment of the freight cargo hold may have been an overlooked factor causing internal cell damage that later erupted in the storage room (e.g. venting, cell wall flex and distortion, expansion of the foil roll, shorting of internal electrodes to foils or case, etc.) A cell may look fine on the outside but be damaged and slow-cooking on the inside. |
As Reuters reports, ANA found damaged wiring in their ELTs.
Japan's ANA Holdings Inc, which operates the world's biggest fleet of Boeing Co Dreamliners, said it found damage to the battery wiring on two 787 locator beacons during checks after the devices were identified as the likely cause of a fire on another aircraft in London this month. |
787 fire investigation looks at pinched battery wiring | Business & Technology | The Seattle Times
"The two sources suggested that Honeywell might have replaced the batteries at some stage before delivery of the jet because the devices sat on the shelf during the years-long 787 program delays." Sat on whose shelf? Are these ELTs 787 specific parts? Or are they used across various models? If its the latter, then I'd expect Honeywell to pull stock and ship it as various orders came in. If the 787 program was a couple of years late, they'd ship units built later on. If it was Boeing's shelf, then who replaced the batteries? If Boeing took possession of the units and shelved them, then they'd be responsible for maintenance. Seeing how this was not standard in-service fleet maintenance, who did they send into the warehouse, screwdriver in hand, to swap the batteries? Given several possible scenarios, this looks like it could be a maintenance procedure problem. Airlines take steps to make sure that work is performed by qualified personnel. because this is a part of their normal business function. But out of sequence manufacturing or maintenance can be a planning headache. |
If it was Boeing's shelf, then who replaced the batteries? If Boeing took possession of the units and shelved them, then they'd be responsible for maintenance. Seeing how this was not standard in-service fleet maintenance, who did they send into the warehouse, screwdriver in hand, to swap the batteries? |
It's probably more complex than this, but, just a thought or two. If the ELT uses a Lithium Magnesium battery, I hope the Magnesium isn't in the same form as was used in "Mag" wheels! Hard to control fires from car wrecks was the reason "Mag" wheels aren't made of Magnesium any longer, but instead are made of Aluminum. . Maybe this type of battery should only be small, for use in low capacity situations, like in smoke detectors, watches, and cameras, so the stored energy isn't enough to burn through routine precautions. I'm sure an alert beacon transmitter would use a lot of current, if it's to transmit for very long, so it probably has a pretty high capacity battery. I've brushed up on my knowledge of different Lithium battery technologies, and it seems like using high capacity ones and/or storing them in close proximity to each other, may be a no no, across the board, until better practices in quality control, design, and use are practiced!
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"It's probably more complex than this,"
To be sure. It's MANGANESE, not MAGNESIUM. And it's in a dioxide form, not elemental. :ugh: |
ANA finds damaged ELT battery wires
Reuters reports:
...ANA...said it found damage to the battery wiring on two 787 locator beacons during checks... The damage was slight, but the beacons have been sent to the manufacturer, Honeywell International Inc, for inspection... |
To be sure. It's MANGANESE, not MAGNESIUM. And it's in a dioxide form, not elemental. :ugh: A Lithium Magnesium battery. I thought I'd read, was the battery in Ancient Mariner's picture, but I could be wrong. Anyway, it didn't seem far fetched, that the ELT might use the same type of battery. Of course, the Magnesium, might not be in it's elemental state either, so could be perfectly safe. |
Magnesium, Manganese, ... What's the difference? |
The type of battery (5 ea /pack) should be one of these:
UHR-CR25650-LVP (U10027) - Battery & Energy Products: Commercial | Ultralife Corporation UHR-CR34610-TSO (U10028, U10029) - Battery & Energy Products: Commercial | Ultralife Corporation |
Coagie:
Magnesium, Manganese, ... What's the difference? Ha, ha ...I didn't know what sort of battery the ELT used, I thought it might have been... All such relevant, and serious, details have been covered in this thread. You would be best served by keeping up before contributing. |
Coagie,
the quoted website also confuses magnesium and manganese: the torqueedo batteries are also Lithium-Mangenese (Mn): This has nothing to do with Magnesium (Mg). |
United finds pinched wiring on ELT also
United Continental Holdings Inc. ( UAL ) said it has found pinched wiring in one Boeing Co. 787 Emergency Location Transmitter as part of Federal Aviation Administration mandated inspections.
The inspections come in the wake of a fire aboard an empty Ethiopian Airlines 787 at Heathrow Airport on July 12. U.K. Investigators recommended inspections as part of its findings. A spokeswoman for United said inspections of its fleet of six 787s are now completed and the "defective" transmitter has been sent back to supplier Honeywell International Inc. ( HON ) for evaluation. The spokeswoman said there was no disruption to United's flight schedule as a result of the inspections. Read more: United Finds Pinched Wiring on Boeing 787 Transmitter GEEZE- Ethiopia, Japan, United - all finding pinched wiring on ELT ?? maybe from same batch- ?? Or did the faster and cheaper mantra catch up with Honey-bucket er Well ?? Or were they produced on a Monday like De-troit cars- after a hangover ?? And about inspection and Q/C ?? |
the quoted website also confuses magnesium and manganese: the torqueedo batteries are also Lithium-Mangenese (Mn): This has nothing to do with Magnesium (Mg) |
All such relevant, and serious, details have been covered in this thread. You would be best served by keeping up before contributing. |
GEEZE- Ethiopia, Japan, United - all finding pinched wiring on ELT ?? maybe from same batch- ?? |
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