lithium explosion

Post by John Larkin
https://www.bbc.com/news/uk-england-london-68744317
It doesn't look like that one was charging.
Lithium battery fires are a big deal in New York too.
San Fancisco is swarming with illegal, unlicensed electric scooters,
surfboards, wheelie things, bikes, and motorcycles.

As the energy density of batteries goes up, failures will
become more spectacular. It's not a good idea to store
both oxidizer and fuel in close proximity in the same
container. It's a recipe for an explosive.

Jeroen Belleman

boB

2024-04-09 03:22:01 UTC

On Mon, 8 Apr 2024 19:03:07 +0200, Jeroen Belleman

LiFePo4 appears to be quite a bit safer than the other lithium ion
types. Not quite as desireable as the flammable versions but quite a
bit safer.

boB

John Larkin

2024-04-12 03:37:50 UTC

On Mon, 8 Apr 2024 19:03:07 +0200, Jeroen Belleman

This is a great idea:

https://www.yahoo.com/tech/researchers-claim-develop-first-calcium-200000395.html

Weave batteries into clothing.

Bill Sloman

2024-04-12 05:19:34 UTC

Lithium batteries don't explode spontaneously.

The "explosion" is actually the last stage in a process that starts when
the batteries start self-discharging more rapidly than they should,
which warms them up a little.

Any properly designed battery management system monitors this
self-heating, with temperature sensors at the core of the battery, and
on it's surface.

If the battery gets hot enough, the higher temperature can lead to a
higher discharge rate, and at a battery temperature between 130C and
160C which depends on the battery chemistry, the process can run away
leading to something that looks like an explosion.

Any properly designed designed battery management system would warn the
user when this were incipient and would start discharging the battery if
it had a safe place to dissipate the stored energy.

It follows that any lithium battery pack that explodes either didn't
have a properly designed battery management system, or was being looked
after by somebody who ignored the early warnings.

All this is too complicated for John Larkin to keep in mind - we've
discussed it here often enough that he should know it by now.

John Larkin doesn't seem to read data-sheets all that carefully, and he
doesn't expect the manufacturers of "electric scooters,surfboards,
wheelie things, bikes, and motorcycles" to be any more careful.

Jeroen Belleman is effectively saying that they should be, but hasn't
spelled out the advantage of using more careful design to cope with the
known dangers of using lithium batteries.

--
Bill Sloman, Sydney

Liz Tuddenham

2024-04-12 08:55:19 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

..was being looked
after by somebody who ignored the early warnings.

That includes 99% of battery users who wouldn't know what to do it they
noticed the warnings or wouldn't be able to do it anyway.

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Bill Sloman

2024-04-12 13:56:47 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

Then it probably needs to include a louder hooter and brilliant flashing
lights to serve the same purpose, if more slowly than a purpose designed
dissipator.

..was being looked
after by somebody who ignored the early warnings.

That includes 99% of battery users who wouldn't know what to do it they
noticed the warnings or wouldn't be able to do it anyway.

A voice message could be pretty explicit. All the message needs to say
is to move the battery outside to where it can't do much damage if it
bursts into flames. EV car batteries are big enough that that's quite a
way, but cars are designed to move appreciable distances.

--
Bill Sloman, Sydney

Liz Tuddenham

2024-04-12 17:39:15 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

Then it probably needs to include a louder hooter and brilliant flashing
lights to serve the same purpose, if more slowly than a purpose designed
dissipator.

..was being looked
after by somebody who ignored the early warnings.

That includes 99% of battery users who wouldn't know what to do it they
noticed the warnings or wouldn't be able to do it anyway.

It's not really a very good selling point. "Oh, by the way, this model
has the latest upgrade and tells you when it is going to explode, so you
can get out of the way".

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Bill Sloman

2024-04-13 15:03:34 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

Then it probably needs to include a louder hooter and brilliant flashing
lights to serve the same purpose, if more slowly than a purpose designed
dissipator.

..was being looked
after by somebody who ignored the early warnings.

That includes 99% of battery users who wouldn't know what to do it they
noticed the warnings or wouldn't be able to do it anyway.

It's not really a very good selling point. "Oh, by the way, this model
has the latest upgrade and tells you when it is going to explode, so you
can get out of the way".

You don't seem to have been paying attention. If you deal with the
warning by discharging the battery, and making it safe, it won't explode.

No stored energy means no dramatic heating, no breaking of the seals
that protect the contents of the battery from atmospheric oxygen, and no
explosion or fire.

Yo do have to get rid of the battery and presumably replace it, but that
was implicit in the original purchase. They aren't sold on the basis
that they are going to last forever.,

--
Bill Sloman, Sydney

Liz Tuddenham

2024-04-13 15:14:07 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

Then it probably needs to include a louder hooter and brilliant flashing
lights to serve the same purpose, if more slowly than a purpose designed
dissipator.

..was being looked
after by somebody who ignored the early warnings.

That includes 99% of battery users who wouldn't know what to do it they
noticed the warnings or wouldn't be able to do it anyway.

It's not really a very good selling point. "Oh, by the way, this model
has the latest upgrade and tells you when it is going to explode, so you
can get out of the way".

You don't seem to have been paying attention. If you deal with the
warning by discharging the battery, and making it safe, it won't explode.

Who it the 'you' in that sentence? Do you mean the average user, in
which case this is a hopeless scenario as most users of batteries
wouldn't have a clue.

Until recently batteries have been inherently safe: unless you did
something stupid they were unlikely to give any trouble. You are now
supporting a type of battery that is inherently unsafe and will catch
fire or explode unless the user takes some positive action. Even if the
user delegates this action to an automated system there is no guarantee
that the action will be taken every time it is needed.

'Safety' that depends on taking a positive action to prevent a disaster
is not safe at all.

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

John Larkin

2024-04-13 16:35:10 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

Then it probably needs to include a louder hooter and brilliant flashing
lights to serve the same purpose, if more slowly than a purpose designed
dissipator.

..was being looked
after by somebody who ignored the early warnings.

That includes 99% of battery users who wouldn't know what to do it they
noticed the warnings or wouldn't be able to do it anyway.

It's not really a very good selling point. "Oh, by the way, this model
has the latest upgrade and tells you when it is going to explode, so you
can get out of the way".

You don't seem to have been paying attention. If you deal with the
warning by discharging the battery, and making it safe, it won't explode.

Who it the 'you' in that sentence? Do you mean the average user, in
which case this is a hopeless scenario as most users of batteries
wouldn't have a clue.
Until recently batteries have been inherently safe: unless you did
something stupid they were unlikely to give any trouble. You are now
supporting a type of battery that is inherently unsafe and will catch
fire or explode unless the user takes some positive action. Even if the
user delegates this action to an automated system there is no guarantee
that the action will be taken every time it is needed.
'Safety' that depends on taking a positive action to prevent a disaster
is not safe at all.

References say that a tiny separator defect spreads radially at
centimeters per second. Any somehow-sensed defect will explode in
flames in well under a minute, from the bad cell into the whole pack.
See Youtube examples... smoke to explosion in seconds.

If I heard an alarm from a lithium battery pack, I wouldn't try to fix
it, I'd run in the opposite direction. What automated system could
discharge an 80 KWH battery pack in a few seconds? Or even 1 KWH?

And a defect sensor would have to constantly snoop every cell of a
pack. A typical Tesla might have 7000 cells.

Bill Sloman

2024-04-14 05:35:10 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

Then it probably needs to include a louder hooter and brilliant flashing
lights to serve the same purpose, if more slowly than a purpose designed
dissipator.

..was being looked
after by somebody who ignored the early warnings.

That includes 99% of battery users who wouldn't know what to do it they
noticed the warnings or wouldn't be able to do it anyway.

It's not really a very good selling point. "Oh, by the way, this model
has the latest upgrade and tells you when it is going to explode, so you
can get out of the way".

You don't seem to have been paying attention. If you deal with the
warning by discharging the battery, and making it safe, it won't explode.

Who it the 'you' in that sentence? Do you mean the average user, in
which case this is a hopeless scenario as most users of batteries
wouldn't have a clue.
Until recently batteries have been inherently safe: unless you did
something stupid they were unlikely to give any trouble. You are now
supporting a type of battery that is inherently unsafe and will catch
fire or explode unless the user takes some positive action. Even if the
user delegates this action to an automated system there is no guarantee
that the action will be taken every time it is needed.
'Safety' that depends on taking a positive action to prevent a disaster
is not safe at all.

References say that a tiny separator defect spreads radially at
centimeters per second.

But you can't provide a link to any such reference.

Google threw up a paper on using airflow to test test battery separators
before they were assembled into a battery, so your defect is going to be
present in new cells, and detectable before they are into assembled
batteries of cells.

Post by John Larkin
Any somehow-sensed defect will explode in
flames in well under a minute, from the bad cell into the whole pack.
See Youtube examples... smoke to explosion in seconds.

Youtube is full of half-baked rubbish, and you are sucker for that.

Post by John Larkin
If I heard an alarm from a lithium battery pack, I wouldn't try to fix
it, I'd run in the opposite direction. What automated system could
discharge an 80 KWH battery pack in a few seconds? Or even 1 KWH?

It doesn't have to discharge it in a few seconds. An increased
self-discharge rate is detectable long before a cell gets to the point
of thermal runaway - the local temperature has to get up to between
130C and 160C - depending on battery type - before it can move into
thermal run-away, so you have plenty of time to make it safe.

Post by John Larkin
And a defect sensor would have to constantly snoop every cell of a
pack. A typical Tesla might have 7000 cells.

It doesn't. It has to snoop the battery core temperature and compare it
with battery surface temperature. A few sensors spread around the core
would let you pick up the existence of hot spots - you wouldn't need to
work out exactly where they were.

The Telsa battery monitors it own core temperature and has built in
resistive heaters to warm it up when outside temperatures are too low to
let it deliver full power at start-up.

--
Bill Sloman, Sydney

KevinJ93

2024-04-14 17:10:31 UTC

....

Post by John Larkin
And a defect sensor would have to constantly snoop every cell of a
pack. A typical Tesla might have 7000 cells.

Tesla (and every other EV manufacturer) does monitor the voltage of
every individual cell and every cell has its own fusible link in case it
becomes shorted.

kw

John Larkin

2024-04-14 20:11:09 UTC

Post by KevinJ93
....

Post by John Larkin
And a defect sensor would have to constantly snoop every cell of a
pack. A typical Tesla might have 7000 cells.

Tesla (and every other EV manufacturer) does monitor the voltage of
every individual cell and every cell has its own fusible link in case it
becomes shorted.
kw

Tesla uses many small cell in parallel, numbers like 74. I wonder how
they could monitor the voltage of each cell.

I assume "becomes shorted" means that the battery terminals are
shorted somehow. The bigger hazard is that a cell will short
internally, and all its paralleled friends will then dump thousands of
amps into it.

Monitoring or fusing won't help a 5-second internal ignition from a
separator failure.

I'm certain that few cheap Chinese bike and scooter batteries have any
sort of safety systems. As they age, they may get more dangerous.

piglet

2024-04-14 20:38:45 UTC

Post by KevinJ93
....

Post by John Larkin
And a defect sensor would have to constantly snoop every cell of a
pack. A typical Tesla might have 7000 cells.

Tesla (and every other EV manufacturer) does monitor the voltage of
every individual cell and every cell has its own fusible link in case it
becomes shorted.
kw

Not if there was a fuse in series with each cell

--
piglet

John Larkin

2024-04-14 20:47:06 UTC

On Sun, 14 Apr 2024 20:38:45 -0000 (UTC), piglet

Post by piglet

Post by KevinJ93
....

Post by John Larkin
And a defect sensor would have to constantly snoop every cell of a
pack. A typical Tesla might have 7000 cells.

Tesla (and every other EV manufacturer) does monitor the voltage of
every individual cell and every cell has its own fusible link in case it
becomes shorted.
kw

Not if there was a fuse in series with each cell

The case stated above is "in case it becomes shorted."

If a cell shorts internally, as they tend to do, no monitoring or
fusing will help. Running will help.

I once worked with a fire alarm company in Freehold, New Jersey. A
sign on the wall said

IN CASE OF FIRE

run, yell FIRE

KevinJ93

2024-04-14 21:56:43 UTC

Post by KevinJ93
....

Post by John Larkin
And a defect sensor would have to constantly snoop every cell of a
pack. A typical Tesla might have 7000 cells.

Tesla (and every other EV manufacturer) does monitor the voltage of
every individual cell and every cell has its own fusible link in case it
becomes shorted.
kw

Tesla uses many small cell in parallel, numbers like 74. I wonder how
they could monitor the voltage of each cell.

As you say many are in parallel in a module (the actual number varies
with the particular model and revision). The cell voltage of all those
cells are the same so can be measured with a single channel of the BMS.

Post by John Larkin
I assume "becomes shorted" means that the battery terminals are
shorted somehow. The bigger hazard is that a cell will short
internally, and all its paralleled friends will then dump thousands of
amps into it.

Each cell has its own fusible link so in that case the link for that
specific cell will blow. The maximum current for an individual cell is
in the region of 40-50A.

In some models Tesla has an overall pyrotechnic fuse to disconnect the
pack from the vehicle very rapidly if there is excess current (>1000A or
so).

Post by John Larkin
Monitoring or fusing won't help a 5-second internal ignition from a
separator failure.

Each cell is in a steel cylinder that can contain a single cell failure
and minimize the probability of cascade failure. A fully-charged cell
contains about 10-20 Wh of energy.

Some car manufacturers use larger format cells with significantly larger
storage per cell.

Post by John Larkin
I'm certain that few cheap Chinese bike and scooter batteries have any
sort of safety systems. As they age, they may get more dangerous.

I believe that some of those use pouch cells (similar to those in
cell-phones, tablets and notebook computers). There is less physical
protection against cascade failure in that case.

kw

Glen Walpert

2024-04-14 23:07:43 UTC

Post by KevinJ93

Post by KevinJ93
....

Post by John Larkin
And a defect sensor would have to constantly snoop every cell of a
pack. A typical Tesla might have 7000 cells.

Tesla (and every other EV manufacturer) does monitor the voltage of
every individual cell and every cell has its own fusible link in case
it becomes shorted.
kw

Tesla uses many small cell in parallel, numbers like 74. I wonder how
they could monitor the voltage of each cell.

Post by John Larkin
I assume "becomes shorted" means that the battery terminals are shorted
somehow. The bigger hazard is that a cell will short internally, and
all its paralleled friends will then dump thousands of amps into it.

Each cell has its own fusible link so in that case the link for that
specific cell will blow. The maximum current for an individual cell is
in the region of 40-50A.
In some models Tesla has an overall pyrotechnic fuse to disconnect the
pack from the vehicle very rapidly if there is excess current (>1000A or
so).

Post by John Larkin
Monitoring or fusing won't help a 5-second internal ignition from a
separator failure.

Each cell is in a steel cylinder that can contain a single cell failure
and minimize the probability of cascade failure. A fully-charged cell
contains about 10-20 Wh of energy.
Some car manufacturers use larger format cells with significantly larger
storage per cell.

Post by John Larkin
I'm certain that few cheap Chinese bike and scooter batteries have any
sort of safety systems. As they age, they may get more dangerous.

I believe that some of those use pouch cells (similar to those in
cell-phones, tablets and notebook computers). There is less physical
protection against cascade failure in that case.
kw

Tesla battery assembly and wiring:

<https://circuitdigest.com/article/tesla-model-s-battery-system-an-
engineers-perspective>

BEV fire risk discussion:

https://spectrum.ieee.org/lithium-ion-battery-fires

Relatively few battery fires actually occur in BEVs, more in hybrids and
/way/ more in scooters. Statistics from insurance companies all seem to
agree, BEV fires are less common than combustion engine vehicle fires:

https://www.popsci.com/technology/electric-vehicle-fire-rates-study/

Have any Tesla batteries burst into flame from a separator failure? All
the Tesla battery fires I have heard of were caused by mechanical damage,
a common cause of fossil fuel fires also.

Bill Sloman

2024-04-14 05:14:39 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

Then it probably needs to include a louder hooter and brilliant flashing
lights to serve the same purpose, if more slowly than a purpose designed
dissipator.

..was being looked
after by somebody who ignored the early warnings.

That includes 99% of battery users who wouldn't know what to do it they
noticed the warnings or wouldn't be able to do it anyway.

It's not really a very good selling point. "Oh, by the way, this model
has the latest upgrade and tells you when it is going to explode, so you
can get out of the way".

You don't seem to have been paying attention. If you deal with the
warning by discharging the battery, and making it safe, it won't explode.

Who it the 'you' in that sentence?

You personally.

Post by Liz Tuddenham
Do you mean the average user, in
which case this is a hopeless scenario as most users of batteries
wouldn't have a clue.
Until recently batteries have been inherently safe: unless you did
something stupid they were unlikely to give any trouble. You are now
supporting a type of battery that is inherently unsafe and will catch
fire or explode unless the user takes some positive action.

But happens to offer a much higher energy density.

It takes a long time to degrade to the point where it can catch fire or
explode, and the degradation is entirely detectable.

Post by Liz Tuddenham
Even if the user delegates this action to an automated system there is no guarantee
that the action will be taken every time it is needed.

And the brakes on your car don't always work, but we do seem to be
willing to live with that.

Post by Liz Tuddenham
'Safety' that depends on taking a positive action to prevent a disaster
is not safe at all.

But we live with that, when the advantages are proportionate to the risk.

--
Bill Sloman, Sydney

Liz Tuddenham

2024-04-14 06:38:53 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

Then it probably needs to include a louder hooter and brilliant flashing
lights to serve the same purpose, if more slowly than a purpose designed
dissipator.

..was being looked
after by somebody who ignored the early warnings.

That includes 99% of battery users who wouldn't know what to do it they
noticed the warnings or wouldn't be able to do it anyway.

It's not really a very good selling point. "Oh, by the way, this model
has the latest upgrade and tells you when it is going to explode, so you
can get out of the way".

You don't seem to have been paying attention. If you deal with the
warning by discharging the battery, and making it safe, it won't explode.

Who it the 'you' in that sentence?

You personally.

But happens to offer a much higher energy density.
It takes a long time to degrade to the point where it can catch fire or
explode, and the degradation is entirely detectable.

Post by Liz Tuddenham
Even if the user delegates this action to an automated system there is
no guarantee that the action will be taken every time it is needed.

And the brakes on your car don't always work, but we do seem to be
willing to live with that.

Post by Liz Tuddenham
'Safety' that depends on taking a positive action to prevent a disaster
is not safe at all.

But we live with that, when the advantages are proportionate to the risk.

My van has dual hydraulic systems for the footbrake, a mechanical
handbrake and even gears that could slow it down in an emergency. If I
park it somewhere, the chance of it crashing into something while I am
not there to stop it is very small indeed, I don't need to take any
positive action.

I suspect the number of spontaneous fires of vehicles with lithium
batteries is far higher in relation to the number on the roads than the
number of spontaneous runaways and crashes of diesel and petrol
vehicles. In addition there is the same risk of brake failure on an
electric vehicle - even more so if it has an electric parking brake
which is the driver cannot operate quickly in an emergency.

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Bill Sloman

2024-04-14 07:19:52 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

Then it probably needs to include a louder hooter and brilliant flashing
lights to serve the same purpose, if more slowly than a purpose designed
dissipator.

..was being looked
after by somebody who ignored the early warnings.

That includes 99% of battery users who wouldn't know what to do it they
noticed the warnings or wouldn't be able to do it anyway.

It's not really a very good selling point. "Oh, by the way, this model
has the latest upgrade and tells you when it is going to explode, so you
can get out of the way".

You don't seem to have been paying attention. If you deal with the
warning by discharging the battery, and making it safe, it won't explode.

Who it the 'you' in that sentence?

You personally.

But happens to offer a much higher energy density.
It takes a long time to degrade to the point where it can catch fire or
explode, and the degradation is entirely detectable.

Post by Liz Tuddenham
Even if the user delegates this action to an automated system there is
no guarantee that the action will be taken every time it is needed.

And the brakes on your car don't always work, but we do seem to be
willing to live with that.

Post by Liz Tuddenham
'Safety' that depends on taking a positive action to prevent a disaster
is not safe at all.

But we live with that, when the advantages are proportionate to the risk.

My van has dual hydraulic systems for the footbrake, a mechanical
handbrake and even gears that could slow it down in an emergency. If I
park it somewhere, the chance of it crashing into something while I am
not there to stop it is very small indeed, I don't need to take any
positive action.
I suspect the number of spontaneous fires of vehicles with lithium
batteries is far higher in relation to the number on the roads than the
number of spontaneous runaways and crashes of diesel and petrol
vehicles.

It isn't - the numbers are quite a bit lower. There have already been
some insurance statistics accumulated and some of them have been posted
here. Electric cars haven't been around for all that long so to some
extent this is comparing relatively new electric cars with a populations
of IC cars which includes some antiquated junk, but electric cars do
seem to be quite a bit safer.

Newspapers don't emphasise this.

Post by Liz Tuddenham
In addition there is the same risk of brake failure on an
electric vehicle - even more so if it has an electric parking brake
which is the driver cannot operate quickly in an emergency.

The point was not the efficacy of the brakes but the existence of a risk
which we are willing to tolerate.

--
Bill Sloman, Sydney

John Larkin

2024-04-12 14:17:37 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

And what if cheap Chinese batteries weren't all designed by geniuses
like Sloman?

Bill Sloman

2024-04-13 05:55:25 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

And what if cheap Chinese batteries weren't all designed by geniuses
like Sloman?

It doesn't take genius to design a decent battery monitoring system, and
manufacturers who sell dangerous products get sued, and banned from
selling into markets with even minimal consumer protection legislation.
Even the US finally banned tetra-ethyl lead as a gasoline additive.

--
Bill Sloman, Sydney

John R Walliker

2024-04-13 22:35:28 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

And what if cheap Chinese batteries weren't all designed by geniuses
like Sloman?

Not entirely. It is still allowed for general aviation.

John

bitrex

2024-04-12 16:31:50 UTC

... if
it had a safe place to dissipate the stored energy.

What if it didn't?

..was being looked
after by somebody who ignored the early warnings.

That includes 99% of battery users who wouldn't know what to do it they
noticed the warnings or wouldn't be able to do it anyway.

It's wild that stuff like that make the national news in the UK.

In the US if I had to pick between the hazard of exploding bikes and
overpenetration I guess it would be a toss up. Glad I wasn't being
treated in the next room for my e-bike injury:

Carlos E.R.

2024-04-12 11:16:40 UTC

Lithium batteries don't explode spontaneously.
The "explosion" is actually the last stage in a process that starts when
the batteries start self-discharging more rapidly than they should,
which warms them up a little.
Any properly designed battery management system monitors this
self-heating, with temperature sensors at the core of the battery, and
on it's surface.
If the battery gets hot enough, the higher temperature can lead to a
higher discharge rate, and at a battery temperature between 130C and
160C which depends on the battery chemistry, the process can run away
leading to something that looks like an explosion.
Any properly designed designed battery management system would warn the
user when this were incipient and would start discharging the battery if
it had a safe place to dissipate the stored energy.
It follows that any lithium battery pack that explodes either didn't
have a properly designed battery management system, or was being looked
after by somebody who ignored the early warnings.
All this is too complicated for John Larkin to keep in mind - we've
discussed it here often enough that he should know it by now.

Or the battery wasn't attended.

Battery fires have happened when nobody was near the battery; maybe
charging.

Here, several cities have prohibited personal electric things with
wheels from entering the urban public transport system after a few fires.

--
Cheers, Carlos.

Bill Sloman

2024-04-12 14:04:53 UTC

Lithium batteries don't explode spontaneously.
The "explosion" is actually the last stage in a process that starts
when the batteries start self-discharging more rapidly than they
should, which warms them up a little.
Any properly designed battery management system monitors this
self-heating, with temperature sensors at the core of the battery, and
on it's surface.
If the battery gets hot enough, the higher temperature can lead to a
higher discharge rate, and at a battery temperature between 130C and
160C which depends on the battery chemistry, the process can run away
leading to something that looks like an explosion.
Any properly designed designed battery management system would warn
the user when this were incipient and would start discharging the
battery if it had a safe place to dissipate the stored energy.
It follows that any lithium battery pack that explodes either didn't
have a properly designed battery management system, or was being
looked after by somebody who ignored the early warnings.
All this is too complicated for John Larkin to keep in mind - we've
discussed it here often enough that he should know it by now.

Or the battery wasn't attended.

Warning systems can be designed to be quite attention getting.

Post by Carlos E.R.
Battery fires have happened when nobody was near the battery; maybe
charging.

A proper battery management system wouldn't let you charge a battery
that had got close to going into thermal runaway

Post by Carlos E.R.
Here, several cities have prohibited personal electric things with
wheels from entering the urban public transport system after a few fires.

A slightly better informed city administration could adopt a more
sensible rule. Personal electric things with wheels can be designed to
be quite unlikely to catch on fire. One's that aren't shouldn't be on
sale in the first place, and would be prohibited imports in any sensible
region.

--
Bill Sloman, Sydney

bitrex

2024-04-12 16:22:00 UTC

Lithium batteries don't explode spontaneously.
The "explosion" is actually the last stage in a process that starts
when the batteries start self-discharging more rapidly than they
should, which warms them up a little.
Any properly designed battery management system monitors this
self-heating, with temperature sensors at the core of the battery,
and on it's surface.
If the battery gets hot enough, the higher temperature can lead to a
higher discharge rate, and at a battery temperature between 130C and
160C which depends on the battery chemistry, the process can run away
leading to something that looks like an explosion.
Any properly designed designed battery management system would warn
the user when this were incipient and would start discharging the
battery if it had a safe place to dissipate the stored energy.
It follows that any lithium battery pack that explodes either didn't
have a properly designed battery management system, or was being
looked after by somebody who ignored the early warnings.
All this is too complicated for John Larkin to keep in mind - we've
discussed it here often enough that he should know it by now.

Or the battery wasn't attended.

Warning systems can be designed to be quite attention getting.

Post by Carlos E.R.
Battery fires have happened when nobody was near the battery; maybe
charging.

A proper battery management system wouldn't let you charge a battery
that had got close to going into thermal runaway

Post by Carlos E.R.
Here, several cities have prohibited personal electric things with
wheels from entering the urban public transport system after a few fires.

The US is the kind of place that will instate outright bans on e bikes,
vape sticks, and books with gay people in them, but in most states it's
perfectly legal to buy crates of fireworks at at time with way more
explosive power than that, on the honor system. Kaboom!

And fretting about the hazards of exploding batteries with 300 million
guns floating around is pretty schizophrenic. Compared to being injured
by an exploding bike (or shot by a stranger for that matter) your
chances of being shot by a police officer are at least the same, or higher.

john larkin

2024-04-12 16:52:27 UTC

Lithium batteries don't explode spontaneously.
The "explosion" is actually the last stage in a process that starts
when the batteries start self-discharging more rapidly than they
should, which warms them up a little.
Any properly designed battery management system monitors this
self-heating, with temperature sensors at the core of the battery,
and on it's surface.
If the battery gets hot enough, the higher temperature can lead to a
higher discharge rate, and at a battery temperature between 130C and
160C which depends on the battery chemistry, the process can run away
leading to something that looks like an explosion.
Any properly designed designed battery management system would warn
the user when this were incipient and would start discharging the
battery if it had a safe place to dissipate the stored energy.
It follows that any lithium battery pack that explodes either didn't
have a properly designed battery management system, or was being
looked after by somebody who ignored the early warnings.
All this is too complicated for John Larkin to keep in mind - we've
discussed it here often enough that he should know it by now.

Or the battery wasn't attended.

Warning systems can be designed to be quite attention getting.

Post by Carlos E.R.
Battery fires have happened when nobody was near the battery; maybe
charging.

A proper battery management system wouldn't let you charge a battery
that had got close to going into thermal runaway

Post by Carlos E.R.
Here, several cities have prohibited personal electric things with
wheels from entering the urban public transport system after a few fires.

The US is the kind of place that will instate outright bans on e bikes,
vape sticks, and books with gay people in them, but in most states it's
perfectly legal to buy crates of fireworks at at time with way more
explosive power than that, on the honor system. Kaboom!
And fretting about the hazards of exploding batteries with 300 million
guns floating around is pretty schizophrenic. Compared to being injured
by an exploding bike (or shot by a stranger for that matter) your
chances of being shot by a police officer are at least the same, or higher.

About 1300 people were killed by police in the US last year, out of a
population of 333 million, about 4 PPM. Cops rarely shoot polite
law-abiding citizens; don't threaten people, especially cops, with
guns or knives.

There were 617 homicides in Chicago last year. I suspect few were
attacks by strangers.

NYC alone had 18 lithium battery fire deaths last year, something like
2 PPM, and that number seems to be trending up.

John Robertson

2024-04-12 17:07:59 UTC

As are most cities with access to Amazon/eBay...(no regulations on what
people can sell on these platforms)

...

Post by bitrex
And fretting about the hazards of exploding batteries with 300 million
guns floating around is pretty schizophrenic. Compared to being injured
by an exploding bike (or shot by a stranger for that matter) your
chances of being shot by a police officer are at least the same, or higher.

Here in Canada the average number of people killed by police annually is
just under 40 per year since 2011. Out of a population of roughly
40,000,000 or 1 PPM in other words.

Perhaps our gun laws do make a difference.

John :-#)#

bitrex

2024-04-12 17:26:30 UTC

As are most cities with access to Amazon/eBay...(no regulations on what
people can sell on these platforms)
...

Here in Canada the average number of people killed by police annually is
just under 40 per year since 2011. Out of a population of roughly
40,000,000 or 1 PPM in other words.
Perhaps our gun laws do make a difference.
John :-#)#

Traffic accidents kill about 50k Americans per year, firearms in the
same ballpark, and Covid is still dropping 500-1k per day.

These fashions of death have been re-categorized as "acts of God" in the
public consciousness.

John Robertson

2024-04-13 07:20:10 UTC

As are most cities with access to Amazon/eBay...(no regulations on
what people can sell on these platforms)
...

Here in Canada the average number of people killed by police annually
is just under 40 per year since 2011. Out of a population of roughly
40,000,000 or 1 PPM in other words.
Perhaps our gun laws do make a difference.
John :-#)#

Traffic accidents kill about 50k Americans per year, firearms in the
same ballpark, and Covid is still dropping 500-1k per day.

US death rate from Covid is around 30/day - not 500 or more! Which is
now about the same as Canada.

Deaths per 100,000 from Covid in Canada was about 1/2 the rate of the
US. Most of those higher rates of death occurred under the previous US
administration.

https://www.worldometers.info/coronavirus/country/us/

John

Post by bitrex
These fashions of death have been re-categorized as "acts of God" in the
public consciousness.

bitrex

2024-04-13 21:41:43 UTC

As are most cities with access to Amazon/eBay...(no regulations on
what people can sell on these platforms)
...

Here in Canada the average number of people killed by police annually
is just under 40 per year since 2011. Out of a population of roughly
40,000,000 or 1 PPM in other words.
Perhaps our gun laws do make a difference.
John :-#)#

Traffic accidents kill about 50k Americans per year, firearms in the
same ballpark, and Covid is still dropping 500-1k per day.

US death rate from Covid is around 30/day - not 500 or more! Which is
now about the same as Canada.

Ope, meant per month, not per day! :B

Post by John Robertson
Deaths per 100,000 from Covid in Canada was about 1/2 the rate of the
US. Most of those higher rates of death occurred under the previous US
administration.
https://www.worldometers.info/coronavirus/country/us/

John Larkin

2024-04-14 01:27:46 UTC

As are most cities with access to Amazon/eBay...(no regulations on what
people can sell on these platforms)
...

Here in Canada the average number of people killed by police annually is
just under 40 per year since 2011. Out of a population of roughly
40,000,000 or 1 PPM in other words.
Perhaps our gun laws do make a difference.
John :-#)#

The population mix makes a bigger difference. Bad guys will always
find guns.

Cursitor Doom

2024-04-14 17:09:46 UTC

On Sat, 13 Apr 2024 18:27:46 -0700, John Larkin

As are most cities with access to Amazon/eBay...(no regulations on what
people can sell on these platforms)
...

Here in Canada the average number of people killed by police annually is
just under 40 per year since 2011. Out of a population of roughly
40,000,000 or 1 PPM in other words.
Perhaps our gun laws do make a difference.
John :-#)#

The population mix makes a bigger difference. Bad guys will always
find guns.

Guns don't kill people. People kill people.

Bill Sloman

2024-04-15 05:14:23 UTC

<snip>

Post by Cursitor Doom

Post by John Larkin
The population mix makes a bigger difference. Bad guys will always
find guns.

Guns don't kill people. People kill people.

This is the NRA mantra.

Guns make it easier for a person to kill more people if that's what the
person chooses to do. Sensible guns control laws tend to keep guns out
of the hands of people who make that choice.

Sydney had such a murderous event on Saturday afternoon - a nut with a
big knife ran around a local shopping center stabbing people. He managed
to kill six people, and he injured nine more including a baby before the
police shot him dead.

If he had had a gun, he would have killed and injured more.

https://www.smh.com.au/national/nsw/bondi-junction-shooting-stabbings-live-updates-police-operation-in-sydney-s-eastern-suburbs-20240413-p5fjku.html

The killer had had mental health issue for quite some time.

--
Bill Sloman, Sydney

John Robertson

2024-04-15 05:58:18 UTC

Post by Cursitor Doom
On Sat, 13 Apr 2024 18:27:46 -0700, John Larkin

As are most cities with access to Amazon/eBay...(no regulations on what
people can sell on these platforms)
...

Here in Canada the average number of people killed by police annually is
just under 40 per year since 2011. Out of a population of roughly
40,000,000 or 1 PPM in other words.
Perhaps our gun laws do make a difference.
John :-#)#

The population mix makes a bigger difference. Bad guys will always
find guns.

If there are guns to be easily found.

Make it harder to find guns, and bad guys can't get them easily. Where
it is easier to procure guns, gun violence is increased. Where it is
harder to get guns, fewer people are killed. Gun dealers don't want that
message getting out though.

I don't think the US has ore bad people than anywhere else. People are
people. Bullies who can't get guns readily are easier to stop.

Post by Cursitor Doom
Guns don't kill people. People kill people.

The correct anecdote would be

"Guns don't kill people (all by themselves), people (find it easier) to
kill people (using guns)."

John

Cursitor Doom

2024-04-15 11:18:47 UTC

Post by Cursitor Doom
On Sat, 13 Apr 2024 18:27:46 -0700, John Larkin

As are most cities with access to Amazon/eBay...(no regulations on what
people can sell on these platforms)
...

Here in Canada the average number of people killed by police annually is
just under 40 per year since 2011. Out of a population of roughly
40,000,000 or 1 PPM in other words.
Perhaps our gun laws do make a difference.
John :-#)#

The population mix makes a bigger difference. Bad guys will always
find guns.

If there are guns to be easily found.
Make it harder to find guns, and bad guys can't get them easily. Where
it is easier to procure guns, gun violence is increased. Where it is
harder to get guns, fewer people are killed. Gun dealers don't want that
message getting out though.
I don't think the US has ore bad people than anywhere else. People are
people. Bullies who can't get guns readily are easier to stop.

Post by Cursitor Doom
Guns don't kill people. People kill people.

The correct anecdote would be
"Guns don't kill people (all by themselves), people (find it easier) to
kill people (using guns)."

That's too verbose, it'll never catch on.

Bill Sloman

2024-04-15 14:51:01 UTC

Post by Cursitor Doom

Post by Cursitor Doom
On Sat, 13 Apr 2024 18:27:46 -0700, John Larkin

As are most cities with access to Amazon/eBay...(no regulations on what
people can sell on these platforms)
...

Here in Canada the average number of people killed by police annually is
just under 40 per year since 2011. Out of a population of roughly
40,000,000 or 1 PPM in other words.
Perhaps our gun laws do make a difference.
John :-#)#

The population mix makes a bigger difference. Bad guys will always
find guns.

If there are guns to be easily found.
Make it harder to find guns, and bad guys can't get them easily. Where
it is easier to procure guns, gun violence is increased. Where it is
harder to get guns, fewer people are killed. Gun dealers don't want that
message getting out though.
I don't think the US has ore bad people than anywhere else. People are
people. Bullies who can't get guns readily are easier to stop.

Post by Cursitor Doom
Guns don't kill people. People kill people.

The correct anecdote would be
"Guns don't kill people (all by themselves), people (find it easier) to
kill people (using guns)."

That's too verbose, it'll never catch on.

It's not the verbosity that's the problem, it's the fact that it sends
different message, and a message that's inconvenient to people who make
money out of making and selling guns, and want to make more money out of
selling even more of them.

That sort of reasoning doesn't appeal to you - you need the lunatic
element to get your turn-on.

--
Bill Sloman, Sydney

Bill Sloman

2024-04-13 06:01:13 UTC

Lithium batteries don't explode spontaneously.
The "explosion" is actually the last stage in a process that starts
when the batteries start self-discharging more rapidly than they
should, which warms them up a little.
Any properly designed battery management system monitors this
self-heating, with temperature sensors at the core of the battery,
and on it's surface.
If the battery gets hot enough, the higher temperature can lead to a
higher discharge rate, and at a battery temperature between 130C and
160C which depends on the battery chemistry, the process can run away
leading to something that looks like an explosion.
Any properly designed designed battery management system would warn
the user when this were incipient and would start discharging the
battery if it had a safe place to dissipate the stored energy.
It follows that any lithium battery pack that explodes either didn't
have a properly designed battery management system, or was being
looked after by somebody who ignored the early warnings.
All this is too complicated for John Larkin to keep in mind - we've
discussed it here often enough that he should know it by now.

Or the battery wasn't attended.

Warning systems can be designed to be quite attention getting.

Post by Carlos E.R.
Battery fires have happened when nobody was near the battery; maybe
charging.

A proper battery management system wouldn't let you charge a battery
that had got close to going into thermal runaway

Post by Carlos E.R.
Here, several cities have prohibited personal electric things with
wheels from entering the urban public transport system after a few fires.

The US is the kind of place that will instate outright bans on e bikes,
vape sticks, and books with gay people in them, but in most states it's
perfectly legal to buy crates of fireworks at at time with way more
explosive power than that, on the honor system. Kaboom!
And fretting about the hazards of exploding batteries with 300 million
guns floating around is pretty schizophrenic. Compared to being injured
by an exploding bike (or shot by a stranger for that matter) your
chances of being shot by a police officer are at least the same, or higher.

About 1300 people were killed by police in the US last year, out of a
population of 333 million, about 4 PPM. Cops rarely shoot polite
law-abiding citizens; don't threaten people, especially cops, with
guns or knives.
There were 617 homicides in Chicago last year. I suspect few were
attacks by strangers.
NYC alone had 18 lithium battery fire deaths last year, something like
2 PPM, and that number seems to be trending up.

If US legislators could understand statistics they'd have introduced
sensible gun control years ago. Finding a form of words that the US
Supreme Court wouldn't object to might have been difficult.

--
Bill Sloman, Sydney

Carlos E.R.

2024-04-13 20:43:01 UTC

Lithium batteries don't explode spontaneously.
The "explosion" is actually the last stage in a process that starts
when the batteries start self-discharging more rapidly than they
should, which warms them up a little.
Any properly designed battery management system monitors this
self-heating, with temperature sensors at the core of the battery,
and on it's surface.
If the battery gets hot enough, the higher temperature can lead to a
higher discharge rate, and at a battery temperature between 130C and
160C which depends on the battery chemistry, the process can run away
leading to something that looks like an explosion.
Any properly designed designed battery management system would warn
the user when this were incipient and would start discharging the
battery if it had a safe place to dissipate the stored energy.
It follows that any lithium battery pack that explodes either didn't
have a properly designed battery management system, or was being
looked after by somebody who ignored the early warnings.
All this is too complicated for John Larkin to keep in mind - we've
discussed it here often enough that he should know it by now.

Or the battery wasn't attended.

Warning systems can be designed to be quite attention getting.

Post by Carlos E.R.
Battery fires have happened when nobody was near the battery; maybe
charging.

A proper battery management system wouldn't let you charge a battery
that had got close to going into thermal runaway

Post by Carlos E.R.
Here, several cities have prohibited personal electric things with
wheels from entering the urban public transport system after a few fires.

It is the only thing they can do until the manufacturers create machines
that do not catch fire putting the entire metro line out of service. It
is not the city transport business or job to mandate what others should
do, or what other regulators do to regulate proper battery building.
They simply have to protect themselves and their users.

(Oh, no guns around here.)

And yes, of course it is a pain. The combination of a personal transport
device and public transportation was working wonderfully for many. You
get from home to the station with your wheelie in minutes, cross the
city in minutes underground, arrive at job place in minutes from the
station using the wheelie again.

--
Cheers, Carlos.

Bill Sloman

2024-04-14 07:11:21 UTC

Lithium batteries don't explode spontaneously.
The "explosion" is actually the last stage in a process that starts
when the batteries start self-discharging more rapidly than they
should, which warms them up a little.
Any properly designed battery management system monitors this
self-heating, with temperature sensors at the core of the battery,
and on it's surface.
If the battery gets hot enough, the higher temperature can lead to a
higher discharge rate, and at a battery temperature between 130C and
160C which depends on the battery chemistry, the process can run
away leading to something that looks like an explosion.
Any properly designed designed battery management system would warn
the user when this were incipient and would start discharging the
battery if it had a safe place to dissipate the stored energy.
It follows that any lithium battery pack that explodes either didn't
have a properly designed battery management system, or was being
looked after by somebody who ignored the early warnings.
All this is too complicated for John Larkin to keep in mind - we've
discussed it here often enough that he should know it by now.

Or the battery wasn't attended.

Warning systems can be designed to be quite attention getting.

Post by Carlos E.R.
Battery fires have happened when nobody was near the battery; maybe
charging.

A proper battery management system wouldn't let you charge a battery
that had got close to going into thermal runaway

Post by Carlos E.R.
Here, several cities have prohibited personal electric things with
wheels from entering the urban public transport system after a few fires.

Most manufacturers produce stuff that doesn't blow up. The rational
approach is to ban only the stuff that might.

Post by Carlos E.R.
And yes, of course it is a pain. The combination of a personal transport
device and public transportation was working wonderfully for many. You
get from home to the station with your wheelie in minutes, cross the
city in minutes underground, arrive at job place in minutes from the
station using the wheelie again.

So ban the cheap junk wheelies that are known to pose a risk of catching
fire and exploding.

--
Bill Sloman, Sydney

John Larkin

2024-04-12 14:21:58 UTC

On Fri, 12 Apr 2024 13:16:40 +0200, "Carlos E.R."

Lithium batteries don't explode spontaneously.
The "explosion" is actually the last stage in a process that starts when
the batteries start self-discharging more rapidly than they should,
which warms them up a little.
Any properly designed battery management system monitors this
self-heating, with temperature sensors at the core of the battery, and
on it's surface.
If the battery gets hot enough, the higher temperature can lead to a
higher discharge rate, and at a battery temperature between 130C and
160C which depends on the battery chemistry, the process can run away
leading to something that looks like an explosion.
Any properly designed designed battery management system would warn the
user when this were incipient and would start discharging the battery if
it had a safe place to dissipate the stored energy.
It follows that any lithium battery pack that explodes either didn't
have a properly designed battery management system, or was being looked
after by somebody who ignored the early warnings.
All this is too complicated for John Larkin to keep in mind - we've
discussed it here often enough that he should know it by now.

Or the battery wasn't attended.
Battery fires have happened when nobody was near the battery; maybe
charging.

Or just parked somewhere, not charging. I wonder how long it takes a
tiny separator defect to spread into an explosive meltdown. Some
references suggest seconds.

Bill Sloman

2024-04-13 06:06:40 UTC

Post by John Larkin
On Fri, 12 Apr 2024 13:16:40 +0200, "Carlos E.R."