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Speedy11(at)aol.com
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 Posted: Wed Sep 20, 2006 9:22 pm Post subject: Bob, no laptops in OBAMs? |
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Is The Burning Battery Problem Solved?
Never Fear... PRBA Is On The Case
[/url]The Portable Rechargeable Battery Association, or PRBA -- did you even know there was such an organization? -- says all the problems with burning batteries of late... in their words... most likely relates to aircraft charging systems.
They describe the risk of using batteries -- even those recalled but not yet returned -- is low, and can be further mitigated by either using the electronic device on battery power alone, or plugging the device into the aircraft power system without the battery installed.
Apparently, PRBA told the FAA about the danger of charging batteries inflight using an aircraft's electrical system almost 10 years ago. In a 1997 letter sent to the airlines and the FAA, the association highlighted the need for stable voltage and an instantaneous cut-off system in the event of an over-heat or over-charge condition.
Most electronic equipment with rechargeable batteries already employ a cut-off system, but they might not work if the user replaces the original battery with one not supplied by the manufacturer... so onboard electrical systems should have a redundant cut-off capability. They don't.
PRBA stresses that even if a battery does catch fire, UK Civil Aviation Authority testing has conclusively proven that standard aviation fire extinquishers can douse the flames. FMI: [url=http://www.prba.org/]http://www.prba.org/ [quote][b]
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nuckollsr(at)cox.net
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| Posted: Thu Sep 21, 2006 5:27 am Post subject: Bob, no laptops in OBAMs? |
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At 01:21 AM 9/21/2006 -0400, you wrote:
| Quote: |
Is The Burning Battery Problem Solved?
Never Fear... PRBA Is On The Case
The Portable Rechargeable Battery Association, or PRBA -- did you even
know there was such an organization? -- says all the problems with burning
batteries of late... in their words... most likely relates to aircraft
charging systems.
|
Except that batteries have caught fire sitting on tables
at electronic products expos. I've heard of one case (but
haven't located a learned narrative) of a computer "burning"
in the overhead compartment of a passenger transport aircraft.
Now, this might have been another kind of failure that caused
the battery to supply energy to smoke other components in the
computer. Given that the world's attention is focused on
battery failures, every instance of smoke from a computer is
likely to be attributed to "battery failure" . . .
| Quote: | They describe the risk of using batteries -- even those recalled but not
yet returned -- is low, and can be further mitigated by either using the
electronic device on battery power alone, or plugging the device into the
aircraft power system without the battery installed.
|
Correct. Documented catastrophic failures of batteries I've read
said the batteries were on-charge at the time.
| Quote: | Apparently, PRBA told the FAA about the danger of charging batteries
inflight using an aircraft's electrical system almost 10 years ago. In a
1997 letter sent to the airlines and the FAA, the association highlighted
the need for stable voltage and an instantaneous cut-off system in the
event of an over-heat or over-charge condition.
|
This pre-supposes that the aircraft energy source for battery
charging (typically 19v DC) is somehow different than the
AC Mains charging source . . .
| Quote: | Most electronic equipment with rechargeable batteries already employ a
cut-off system, but they might not work if the user replaces the original
battery with one not supplied by the manufacturer... so onboard electrical
systems should have a redundant cut-off capability. They don't.
|
Not sure what this would be. The AC Mains power supplies for laptops
are little switchmode power supplies that produce some lower level
DC, typically 16-20 volts at a couple of amps. The wires comiing out
of the power supplies on every computer I've owned was a simple (+) and
(-) DC power . . . no third wire to exchange any sort or intelligence
between computer mounted battery and the external power supply.
It's true that most if not all new products are fitted with "smart
batteries" . . . they have a microcontroller in the battery to
track incoming and outgoing power and convert the data to state
of charge information for the computer's on-board power supply and
charging circuits. Hence one will observe that battery packs for
their modern portables have multi-pin conntectors for the purpose
of exchanging both DC power and intelligence about battery management.
| Quote: | PRBA stresses that even if a battery does catch fire, UK Civil Aviation
Authority testing has conclusively proven that standard aviation fire
extinquishers can douse the flames.
|
That's a comfort. Does anyone carry a "standard aviation fire
extinguisher" in their airplane?
The risks are quite low. The infamous failed batteries are of a unique
Li-Ion technology particularly vulnerable to the failure mode
being examined. I'm working with Concorde and others to evaluate
the potential future of Li-Ion batteries in aircraft. I've proposed
a battery test program (in my van with a 24/7 DAS recording
temperature, input/output current and voltage) to see how hard
it is to 'beat up' a small array of Li-Ion cells.
In the mean time, I'll suggest that use of a lap-top aboard
passenger transport aircraft offers a unique hazard: When
the passenger in front of you reclines the seat, you're
in danger of injury to the diaphragm if not asphyxiation
by crushing. My lap-tops stay in the overhead and I do my
writing with a theme-book and pencil.
Bob . . .
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
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nuckollsr(at)cox.net
Guest
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| Posted: Thu Sep 21, 2006 11:16 am Post subject: Bob, no laptops in OBAMs? |
|
|
At 01:21 AM 9/21/2006 -0400, you wrote:
| Quote: |
Is The Burning Battery Problem Solved?
Never Fear... PRBA Is On The Case
The Portable Rechargeable Battery Association, or PRBA -- did you even
know there was such an organization? -- says all the problems with burning
batteries of late... in their words... most likely relates to aircraft
charging systems.
|
Except that batteries have caught fire sitting on tables
at electronic products expos. I've heard of one case (but
haven't located a learned narrative) of a computer "burning"
in the overhead compartment of a passenger transport aircraft.
Now, this might have been another kind of failure that caused
the battery to supply energy to smoke other components in the
computer. Given that the world's attention is focused on
battery failures, every instance of smoke from a computer is
likely to be attributed to "battery failure" . . .
| Quote: | They describe the risk of using batteries -- even those recalled but not
yet returned -- is low, and can be further mitigated by either using the
electronic device on battery power alone, or plugging the device into the
aircraft power system without the battery installed.
|
Correct. Documented catastrophic failures of batteries I've read
said the batteries were on-charge at the time.
| Quote: | Apparently, PRBA told the FAA about the danger of charging batteries
inflight using an aircraft's electrical system almost 10 years ago. In a
1997 letter sent to the airlines and the FAA, the association highlighted
the need for stable voltage and an instantaneous cut-off system in the
event of an over-heat or over-charge condition.
|
This pre-supposes that the aircraft energy source for battery
charging (typically 19v DC) is somehow different than the
AC Mains charging source . . .
| Quote: | Most electronic equipment with rechargeable batteries already employ a
cut-off system, but they might not work if the user replaces the original
battery with one not supplied by the manufacturer... so onboard electrical
systems should have a redundant cut-off capability. They don't.
|
Not sure what this would be. The AC Mains power supplies for laptops
are little switchmode power supplies that produce some lower level
DC, typically 16-20 volts at a couple of amps. The wires comiing out
of the power supplies on every computer I've owned was a simple (+) and
(-) DC power . . . no third wire to exchange any sort or intelligence
between computer mounted battery and the external power supply.
It's true that most if not all new products are fitted with "smart
batteries" . . . they have a microcontroller in the battery to
track incoming and outgoing power and convert the data to state
of charge information for the computer's on-board power supply and
charging circuits. Hence one will observe that battery packs for
their modern portables have multi-pin conntectors for the purpose
of exchanging both DC power and intelligence about battery management.
| Quote: | PRBA stresses that even if a battery does catch fire, UK Civil Aviation
Authority testing has conclusively proven that standard aviation fire
extinquishers can douse the flames.
|
That's a comfort. Does anyone carry a "standard aviation fire
extinguisher" in their airplane?
The risks are quite low. The infamous failed batteries are of a unique
Li-Ion technology particularly vulnerable to the failure mode
being examined. I'm working with Concorde and others to evaluate
the potential future of Li-Ion batteries in aircraft. I've proposed
a battery test program (in my van with a 24/7 DAS recording
temperature, input/output current and voltage) to see how hard
it is to 'beat up' a small array of Li-Ion cells.
In the mean time, I'll suggest that use of a lap-top aboard
passenger transport aircraft offers a unique hazard: When
the passenger in front of you reclines the seat, you're
in danger of injury to the diaphragm if not asphyxiation
by crushing. My lap-tops stay in the overhead and I do my
writing with a theme-book and pencil.
Bob . . .
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
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