Li-Polymer Batteries

[rickman]

I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone know?

http://www.ebay.com/itm/201761814378

I've tried asking the vendor but they just keep telling me to read the
description. Any ideas of what these numbers mean?

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[Mark Storkamp]

In article <os2f0c$8t0$1@dont-email.me>, rickman <gnuarm@gmail.com>
wrote:

I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone know?

http://www.ebay.com/itm/201761814378

I've tried asking the vendor but they just keep telling me to read the
description. Any ideas of what these numbers mean?

Looks like the outside dimensions, 3.5 x 70 x 90 vs 3.5 x 70 x 95.

--

 

[rickman]

Mark Storkamp wrote on 10/16/2017 1:47 PM:

In article <os2f0c$8t0$1@dont-email.me>, rickman <gnuarm@gmail.com
wrote:

I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone know?

http://www.ebay.com/itm/201761814378

I've tried asking the vendor but they just keep telling me to read the
description. Any ideas of what these numbers mean?

Looks like the outside dimensions, 3.5 x 70 x 90 vs 3.5 x 70 x 95.

Duh! Thanks. Now to figure out why they are a different size. Could that
be the protection circuit board? They say these cells include protection,
but maybe that is not entirely accurate?

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[rickman]

rickman wrote on 10/16/2017 10:16 AM:

I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone know?

http://www.ebay.com/itm/201761814378

I've tried asking the vendor but they just keep telling me to read the
description. Any ideas of what these numbers mean?

I got an answer to the question above.

One thing that concerns me about lithium cells is their nature to catch fire
and the way they are almost explosive when they do. I'm thinking of making
a box for them of aluminum sheet. This will contain a fire if a cell
ruptures, but not the heat. I don't have a lot of space to add insulation,
but I could add a layer of something that would absorb the heat at least on
the side that would be in contact with anything. I'm wondering what would
be a good insulating or heat absorbing layer. In the old days I would wrap
the box in an asbestos cloth, but I expect they aren't used any more.

I found some half inch thick Ceramic Fiber Blanket on eBay for $10. This
looks like it could help insulate a run away battery. But when I look at a
data sheet, I'm not sure it will keep the outer plastic case from melting
and/or catching fire. They give a temperature rise, but don't say how long
they allowed before taking the measurement. They cite ASTM Test Procedure
C-177, but I haven't dug that up yet to see how it is done.

What else would be an option? It should be cheap and available.

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[rickman]

rickman wrote on 10/17/2017 1:30 AM:

rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone
know?

http://www.ebay.com/itm/201761814378

I've tried asking the vendor but they just keep telling me to read the
description. Any ideas of what these numbers mean?

I got an answer to the question above.

One thing that concerns me about lithium cells is their nature to catch fire
and the way they are almost explosive when they do. I'm thinking of making
a box for them of aluminum sheet. This will contain a fire if a cell
ruptures, but not the heat. I don't have a lot of space to add insulation,
but I could add a layer of something that would absorb the heat at least on
the side that would be in contact with anything. I'm wondering what would
be a good insulating or heat absorbing layer. In the old days I would wrap
the box in an asbestos cloth, but I expect they aren't used any more.

I found some half inch thick Ceramic Fiber Blanket on eBay for $10. This
looks like it could help insulate a run away battery. But when I look at a
data sheet, I'm not sure it will keep the outer plastic case from melting
and/or catching fire. They give a temperature rise, but don't say how long
they allowed before taking the measurement. They cite ASTM Test Procedure
C-177, but I haven't dug that up yet to see how it is done.

What else would be an option? It should be cheap and available.

This looks interesting and it would be easy to install. They say it will
tolerate 800°C for 5 mins and a lithium battery in runaway would hit 600°C.

http://www.ebay.com/itm/171761074567

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[Jan Panteltje]

On a sunny day (Tue, 17 Oct 2017 01:30:45 -0400) it happened rickman
<gnuarm@gmail.com> wrote in <os44i7$p0f$1@dont-email.me>:

rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone know?

http://www.ebay.com/itm/201761814378

It has build in chips to protect it, very unlikely to cath fire if you use a decent charger chip.

 

[rickman]

Jan Panteltje wrote on 10/17/2017 4:13 AM:

On a sunny day (Tue, 17 Oct 2017 01:30:45 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os44i7$p0f$1@dont-email.me>:

rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone know?

http://www.ebay.com/itm/201761814378

It has build in chips to protect it, very unlikely to cath fire if you use a decent charger chip.

"Very unlikely" is fine when it is sitting on your desk. If that happens
you get an appropriate fire extinguisher and put it out or at least let it
burn and put out anything else it has ignited. If you are in a vehicle
where you have no means of escaping and no way to deal with the fire, you
are SOL. "Very unlikely" isn't good enough for me.

Also, I'm not convinced all of these units have protection. The two model
numbers would seem to indicate one is 5 mm longer than the other. I expect
this is exactly the size of the protection board, so one might have
protection and the other might not. It is not all that unusual for an eBay
listing to contain errors and complete lies^H^H^H^H^H alternate facts.

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[Jan Panteltje]

On a sunny day (Tue, 17 Oct 2017 05:21:15 -0400) it happened rickman
<gnuarm@gmail.com> wrote in <os4i2d$cgp$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 4:13 AM:
On a sunny day (Tue, 17 Oct 2017 01:30:45 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os44i7$p0f$1@dont-email.me>:

rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone know?

http://www.ebay.com/itm/201761814378

It has build in chips to protect it, very unlikely to cath fire if you use a decent charger chip.

"Very unlikely" is fine when it is sitting on your desk. If that happens
you get an appropriate fire extinguisher and put it out or at least let it
burn and put out anything else it has ignited. If you are in a vehicle
where you have no means of escaping and no way to deal with the fire, you
are SOL. "Very unlikely" isn't good enough for me.

Na, wrap your nuclear plants in ..

Also, I'm not convinced all of these units have protection. The two model
numbers would seem to indicate one is 5 mm longer than the other. I expect
this is exactly the size of the protection board, so one might have
protection and the other might not. It is not all that unusual for an eBay
listing to contain errors and complete lies^H^H^H^H^H alternate facts.

True, I only looked at the link, you can see the protection board,
I have some like that, but only 1000 mAh, marked 'Varta'.
From China nevertheless.

I have some without protection board too...more RC type single cell lipos.
And then I have the 3 cell ones, 30C ... no protection either.
Danger all around me,
Oh and the box with LiIon super powerfull forgot how many C.

Gotta run

Think about it, you find lipos everywhere, even in those blutooth earplugs /
headsets for your cellphone, and happily plug it in your ear and wear it on your head.
Cars have gasoline, bad things can happen...
There is a mad dog president in control of the button, I would worry about that first.
Probabilities.

 

[rickman]

Jan Panteltje wrote on 10/17/2017 5:47 AM:

On a sunny day (Tue, 17 Oct 2017 05:21:15 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4i2d$cgp$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 4:13 AM:
On a sunny day (Tue, 17 Oct 2017 01:30:45 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os44i7$p0f$1@dont-email.me>:

rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone know?

http://www.ebay.com/itm/201761814378

It has build in chips to protect it, very unlikely to cath fire if you use a decent charger chip.

"Very unlikely" is fine when it is sitting on your desk. If that happens
you get an appropriate fire extinguisher and put it out or at least let it
burn and put out anything else it has ignited. If you are in a vehicle
where you have no means of escaping and no way to deal with the fire, you
are SOL. "Very unlikely" isn't good enough for me.

Na, wrap your nuclear plants in ..


Also, I'm not convinced all of these units have protection. The two model
numbers would seem to indicate one is 5 mm longer than the other. I expect
this is exactly the size of the protection board, so one might have
protection and the other might not. It is not all that unusual for an eBay
listing to contain errors and complete lies^H^H^H^H^H alternate facts.

True, I only looked at the link, you can see the protection board,
I have some like that, but only 1000 mAh, marked 'Varta'.
From China nevertheless.

I have some without protection board too...more RC type single cell lipos.
And then I have the 3 cell ones, 30C ... no protection either.
Danger all around me,
Oh and the box with LiIon super powerfull forgot how many C.

Gotta run

Think about it, you find lipos everywhere, even in those blutooth earplugs /
headsets for your cellphone, and happily plug it in your ear and wear it on your head.
Cars have gasoline, bad things can happen...
There is a mad dog president in control of the button, I would worry about that first.
Probabilities.

I seem to recall a number of professional designs from companies who have
much reputation to loose which burst into flames.

So no, I don't have tons of confidence in Lithium batteries to the extent
that I want to strap one on my kayak with no physical protection against the
boat catching on fire.

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[Jan Panteltje]

On a sunny day (Tue, 17 Oct 2017 06:18:09 -0400) it happened rickman
<gnuarm@gmail.com> wrote in <os4lda$4hi$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 5:47 AM:
On a sunny day (Tue, 17 Oct 2017 05:21:15 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4i2d$cgp$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 4:13 AM:
On a sunny day (Tue, 17 Oct 2017 01:30:45 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os44i7$p0f$1@dont-email.me>:

rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone know?

http://www.ebay.com/itm/201761814378

It has build in chips to protect it, very unlikely to cath fire if you use a decent charger chip.

"Very unlikely" is fine when it is sitting on your desk. If that happens
you get an appropriate fire extinguisher and put it out or at least let it
burn and put out anything else it has ignited. If you are in a vehicle
where you have no means of escaping and no way to deal with the fire, you
are SOL. "Very unlikely" isn't good enough for me.

Na, wrap your nuclear plants in ..


Also, I'm not convinced all of these units have protection. The two model
numbers would seem to indicate one is 5 mm longer than the other. I expect
this is exactly the size of the protection board, so one might have
protection and the other might not. It is not all that unusual for an eBay
listing to contain errors and complete lies^H^H^H^H^H alternate facts.

True, I only looked at the link, you can see the protection board,
I have some like that, but only 1000 mAh, marked 'Varta'.
From China nevertheless.

I have some without protection board too...more RC type single cell lipos.
And then I have the 3 cell ones, 30C ... no protection either.
Danger all around me,
Oh and the box with LiIon super powerfull forgot how many C.

Gotta run

Think about it, you find lipos everywhere, even in those blutooth earplugs /
headsets for your cellphone, and happily plug it in your ear and wear it on your head.
Cars have gasoline, bad things can happen...
There is a mad dog president in control of the button, I would worry about that first.
Probabilities.

I seem to recall a number of professional designs from companies who have
much reputation to loose which burst into flames.

Was it not Liion?

So no, I don't have tons of confidence in Lithium batteries to the extent
that I want to strap one on my kayak with no physical protection against the
boat catching on fire.

Well just roll.

 

[rickman]

Jan Panteltje wrote on 10/17/2017 6:26 AM:

On a sunny day (Tue, 17 Oct 2017 06:18:09 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4lda$4hi$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 5:47 AM:
On a sunny day (Tue, 17 Oct 2017 05:21:15 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4i2d$cgp$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 4:13 AM:
On a sunny day (Tue, 17 Oct 2017 01:30:45 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os44i7$p0f$1@dont-email.me>:

rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone know?

http://www.ebay.com/itm/201761814378

It has build in chips to protect it, very unlikely to cath fire if you use a decent charger chip.

"Very unlikely" is fine when it is sitting on your desk. If that happens
you get an appropriate fire extinguisher and put it out or at least let it
burn and put out anything else it has ignited. If you are in a vehicle
where you have no means of escaping and no way to deal with the fire, you
are SOL. "Very unlikely" isn't good enough for me.

Na, wrap your nuclear plants in ..


Also, I'm not convinced all of these units have protection. The two model
numbers would seem to indicate one is 5 mm longer than the other. I expect
this is exactly the size of the protection board, so one might have
protection and the other might not. It is not all that unusual for an eBay
listing to contain errors and complete lies^H^H^H^H^H alternate facts.

True, I only looked at the link, you can see the protection board,
I have some like that, but only 1000 mAh, marked 'Varta'.
From China nevertheless.

I have some without protection board too...more RC type single cell lipos.
And then I have the 3 cell ones, 30C ... no protection either.
Danger all around me,
Oh and the box with LiIon super powerfull forgot how many C.

Gotta run

Think about it, you find lipos everywhere, even in those blutooth earplugs /
headsets for your cellphone, and happily plug it in your ear and wear it on your head.
Cars have gasoline, bad things can happen...
There is a mad dog president in control of the button, I would worry about that first.
Probabilities.

I seem to recall a number of professional designs from companies who have
much reputation to loose which burst into flames.

Was it not Liion?



So no, I don't have tons of confidence in Lithium batteries to the extent
that I want to strap one on my kayak with no physical protection against the
boat catching on fire.

Well just roll.

I seem to recall Lithium doesn't do so well in contact with water.

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[TTman]

On 17/10/2017 06:30, rickman wrote:

rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095.  I can't find any
references anywhere that describe what these model numbers mean.
Anyone know?

http://www.ebay.com/itm/201761814378

I've tried asking the vendor but they just keep telling me to read the
description.  Any ideas of what these numbers mean?

SNIP
They say that the battery is fully protected internally... over voltage,
undervoltage and over current so should be perfectly safe....

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

[Jan Panteltje]

On a sunny day (Tue, 17 Oct 2017 06:33:15 -0400) it happened rickman
<gnuarm@gmail.com> wrote in <os4m9d$971$1@dont-email.me>:

I seem to recall a number of professional designs from companies who have
much reputation to loose which burst into flames.

Was it not Liion?



So no, I don't have tons of confidence in Lithium batteries to the extent
that I want to strap one on my kayak with no physical protection against the
boat catching on fire.

Well just roll.

I seem to recall Lithium doesn't do so well in contact with water.

Have not had any Li fires, so don't know, but youtube has the answer:
https://www.youtube.com/watch?v=vRKK6pliejs

So what can you do in a kayak? water proof bottle:
http://panteltje.com/pub/a_seaworthy_GPS_radiation_counter_IMG_4447.JPG
Remember I hold the Usenet patent on that

 

[mike]

On 10/17/2017 3:33 AM, rickman wrote:

Jan Panteltje wrote on 10/17/2017 6:26 AM:
On a sunny day (Tue, 17 Oct 2017 06:18:09 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4lda$4hi$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 5:47 AM:
On a sunny day (Tue, 17 Oct 2017 05:21:15 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4i2d$cgp$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 4:13 AM:
On a sunny day (Tue, 17 Oct 2017 01:30:45 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os44i7$p0f$1@dont-email.me>:

rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and
they ask the
buyer to choose between battery types 357090 & 357095. I can't
find any
references anywhere that describe what these model numbers
mean. Anyone know?

http://www.ebay.com/itm/201761814378

It has build in chips to protect it, very unlikely to cath fire if
you use a decent charger chip.

"Very unlikely" is fine when it is sitting on your desk. If that
happens
you get an appropriate fire extinguisher and put it out or at least
let it
burn and put out anything else it has ignited. If you are in a
vehicle
where you have no means of escaping and no way to deal with the
fire, you
are SOL. "Very unlikely" isn't good enough for me.

Na, wrap your nuclear plants in ..


Also, I'm not convinced all of these units have protection. The
two model
numbers would seem to indicate one is 5 mm longer than the other.
I expect
this is exactly the size of the protection board, so one might have
protection and the other might not. It is not all that unusual for
an eBay
listing to contain errors and complete lies^H^H^H^H^H alternate facts.

True, I only looked at the link, you can see the protection board,
I have some like that, but only 1000 mAh, marked 'Varta'.
From China nevertheless.

I have some without protection board too...more RC type single cell
lipos.
And then I have the 3 cell ones, 30C ... no protection either.
Danger all around me,
Oh and the box with LiIon super powerfull forgot how many C.

Gotta run

Think about it, you find lipos everywhere, even in those blutooth
earplugs /
headsets for your cellphone, and happily plug it in your ear and
wear it on your head.
Cars have gasoline, bad things can happen...
There is a mad dog president in control of the button, I would worry
about that first.
Probabilities.

I seem to recall a number of professional designs from companies who
have
much reputation to loose which burst into flames.

Was it not Liion?



So no, I don't have tons of confidence in Lithium batteries to the
extent
that I want to strap one on my kayak with no physical protection
against the
boat catching on fire.

Well just roll.

I seem to recall Lithium doesn't do so well in contact with water.

Interesting to see how far people will go to ignore the total system
and focus on one ill-conceived component.
The devil is in the details, and we have few.

Do the math.
How much energy is released in a battery fire?
If you insulate it, how hot will it get inside, since you've
guaranteed thermal runaway?
How much energy is released as heat if you discharge the battery
at maximum current allowed by your current limit strategy?
What does that do to the cell temperature if you insulate it?

How often are you gonna use this kayak device?
Can you not throw it overboard if it catches fire?
I submit that the release mechanism is far more likely
to jamb than the battery is to catch fire. ;-)

Given your paranoia, might a NiMH or Alkaline AA cell pack
be more cost effective and weigh less and take up less space
than your protection vault and fire suppression apparatus and floating
burn unit to treat the injured? Maybe you should have two burn
units just in case one of the doctors has a heart attack.

I surmise that there are some devices sold on EBAY that are made
from tested/fully compliant components and do what they say.
Problem is that you can't tell which.

Battery protection built into the battery won't solve your problem.
It's there as a backup to your own carefully crafted redundant
battery management system. I'm not saying you shouldn't have it.
I'm saying that you shouldn't rely on it.

The good news is that you are very much more likely to drown
than to catch fire.

 

[Tom Gardner]

On 17/10/17 11:18, rickman wrote:

Jan Panteltje wrote on 10/17/2017 5:47 AM:
On a sunny day (Tue, 17 Oct 2017 05:21:15 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4i2d$cgp$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 4:13 AM:
On a sunny day (Tue, 17 Oct 2017 01:30:45 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os44i7$p0f$1@dont-email.me>:

rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone
know?

http://www.ebay.com/itm/201761814378

It has build in chips to protect it, very unlikely to cath fire if you use a
decent charger chip.

"Very unlikely" is fine when it is sitting on your desk. If that happens
you get an appropriate fire extinguisher and put it out or at least let it
burn and put out anything else it has ignited. If you are in a vehicle
where you have no means of escaping and no way to deal with the fire, you
are SOL. "Very unlikely" isn't good enough for me.

Na, wrap your nuclear plants in ..


Also, I'm not convinced all of these units have protection. The two model
numbers would seem to indicate one is 5 mm longer than the other. I expect
this is exactly the size of the protection board, so one might have
protection and the other might not. It is not all that unusual for an eBay
listing to contain errors and complete lies^H^H^H^H^H alternate facts.

True, I only looked at the link, you can see the protection board,
I have some like that, but only 1000 mAh, marked 'Varta'.
From China nevertheless.

I have some without protection board too...more RC type single cell lipos.
And then I have the 3 cell ones, 30C ... no protection either.
Danger all around me,
Oh and the box with LiIon super powerfull forgot how many C.

Gotta run

Think about it, you find lipos everywhere, even in those blutooth earplugs /
headsets for your cellphone, and happily plug it in your ear and wear it on
your head.
Cars have gasoline, bad things can happen...
There is a mad dog president in control of the button, I would worry about
that first.
Probabilities.

I seem to recall a number of professional designs from companies who have much
reputation to loose which burst into flames.

So no, I don't have tons of confidence in Lithium batteries to the extent that I
want to strap one on my kayak with no physical protection against the boat
catching on fire.

Here's the authoritative report of one example of an *aerospace*
qualified battery fire. The pilot was dead (ho ho) lucky the fire
only occurred after landing.

https://assets.publishing.service.gov.uk/media/59c8f175e5274a49c07f4704/AAIB_S3-2017_G-GSGS.pdf

The pictures in the report are informative.

 

[rickman]

Jan Panteltje wrote on 10/17/2017 11:31 AM:

On a sunny day (Tue, 17 Oct 2017 06:33:15 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4m9d$971$1@dont-email.me>:

I seem to recall a number of professional designs from companies who have
much reputation to loose which burst into flames.

Was it not Liion?



So no, I don't have tons of confidence in Lithium batteries to the extent
that I want to strap one on my kayak with no physical protection against the
boat catching on fire.

Well just roll.

I seem to recall Lithium doesn't do so well in contact with water.

Have not had any Li fires, so don't know, but youtube has the answer:
https://www.youtube.com/watch?v=vRKK6pliejs

So what can you do in a kayak? water proof bottle:
http://panteltje.com/pub/a_seaworthy_GPS_radiation_counter_IMG_4447.JPG
Remember I hold the Usenet patent on that

There are so many things wrong with this I have to assume you are joking
with me.

Lithium is highly reactive with water. It is stored in oil or under Argon
to exclude water. Take that seriously.

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[rickman]

Jan Panteltje wrote on 10/17/2017 11:31 AM:

On a sunny day (Tue, 17 Oct 2017 06:33:15 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4m9d$971$1@dont-email.me>:

I seem to recall a number of professional designs from companies who have
much reputation to loose which burst into flames.

Was it not Liion?



So no, I don't have tons of confidence in Lithium batteries to the extent
that I want to strap one on my kayak with no physical protection against the
boat catching on fire.

Well just roll.

I seem to recall Lithium doesn't do so well in contact with water.

Have not had any Li fires, so don't know, but youtube has the answer:
https://www.youtube.com/watch?v=vRKK6pliejs

So what can you do in a kayak? water proof bottle:
http://panteltje.com/pub/a_seaworthy_GPS_radiation_counter_IMG_4447.JPG
Remember I hold the Usenet patent on that

Oh yeah, Lithium sometimes fools the experts.

https://en.wikipedia.org/wiki/Castle_Bravo

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[rickman]

mike wrote on 10/17/2017 3:07 PM:

On 10/17/2017 3:33 AM, rickman wrote:
Jan Panteltje wrote on 10/17/2017 6:26 AM:
On a sunny day (Tue, 17 Oct 2017 06:18:09 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4lda$4hi$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 5:47 AM:
On a sunny day (Tue, 17 Oct 2017 05:21:15 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4i2d$cgp$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 4:13 AM:
On a sunny day (Tue, 17 Oct 2017 01:30:45 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os44i7$p0f$1@dont-email.me>:

rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and
they ask the
buyer to choose between battery types 357090 & 357095. I can't
find any
references anywhere that describe what these model numbers
mean. Anyone know?

http://www.ebay.com/itm/201761814378

It has build in chips to protect it, very unlikely to cath fire if
you use a decent charger chip.

"Very unlikely" is fine when it is sitting on your desk. If that
happens
you get an appropriate fire extinguisher and put it out or at least
let it
burn and put out anything else it has ignited. If you are in a
vehicle
where you have no means of escaping and no way to deal with the
fire, you
are SOL. "Very unlikely" isn't good enough for me.

Na, wrap your nuclear plants in ..


Also, I'm not convinced all of these units have protection. The
two model
numbers would seem to indicate one is 5 mm longer than the other.
I expect
this is exactly the size of the protection board, so one might have
protection and the other might not. It is not all that unusual for
an eBay
listing to contain errors and complete lies^H^H^H^H^H alternate facts.

True, I only looked at the link, you can see the protection board,
I have some like that, but only 1000 mAh, marked 'Varta'.
From China nevertheless.

I have some without protection board too...more RC type single cell
lipos.
And then I have the 3 cell ones, 30C ... no protection either.
Danger all around me,
Oh and the box with LiIon super powerfull forgot how many C.

Gotta run

Think about it, you find lipos everywhere, even in those blutooth
earplugs /
headsets for your cellphone, and happily plug it in your ear and
wear it on your head.
Cars have gasoline, bad things can happen...
There is a mad dog president in control of the button, I would worry
about that first.
Probabilities.

I seem to recall a number of professional designs from companies who
have
much reputation to loose which burst into flames.

Was it not Liion?



So no, I don't have tons of confidence in Lithium batteries to the
extent
that I want to strap one on my kayak with no physical protection
against the
boat catching on fire.

Well just roll.

I seem to recall Lithium doesn't do so well in contact with water.

Interesting to see how far people will go to ignore the total system
and focus on one ill-conceived component.
The devil is in the details, and we have few.

Not sure what you mean about ignoring the "system"?

Do the math.
How much energy is released in a battery fire?

A lithium batter will release a *lot* more heat than just what is stored in
the battery. Even discharged lithium batteries have to be stored safely.

If you insulate it, how hot will it get inside, since you've
guaranteed thermal runaway?

Don't care, the concern is to prevent the China syndrome where the battery
burns its case and melts though my boat. High density polyethylene won't
stand up to a lithium fire, or any other type of fire for that matter.

How much energy is released as heat if you discharge the battery
at maximum current allowed by your current limit strategy?
What does that do to the cell temperature if you insulate it?

The unit won't be drawing the maximum current. There will be protection to
prevent this. The load will be relatively light compared to the C value.
I'm interested in a long discharge time.

How often are you gonna use this kayak device?
Can you not throw it overboard if it catches fire?

Not very easily. It will be securely affixed to the bow of a 17 foot kayak
with me in the middle. My arms aren't 8 foot long.

I submit that the release mechanism is far more likely
to jamb than the battery is to catch fire. ;-)

A great reason to prevent a fire from becoming catastrophic.

Given your paranoia, might a NiMH or Alkaline AA cell pack
be more cost effective and weigh less and take up less space
than your protection vault and fire suppression apparatus and floating
burn unit to treat the injured? Maybe you should have two burn
units just in case one of the doctors has a heart attack.

That would be a good idea, but NiMH cells don't have the density. But that
might not be a significant issue. But the circuits to use NiMH in a device
like this aren't so common.

I surmise that there are some devices sold on EBAY that are made
from tested/fully compliant components and do what they say.
Problem is that you can't tell which.

Battery protection built into the battery won't solve your problem.
It's there as a backup to your own carefully crafted redundant
battery management system. I'm not saying you shouldn't have it.
I'm saying that you shouldn't rely on it.

Yes, and the battery charger/step up circuit also incorporates protection.

The good news is that you are very much more likely to drown
than to catch fire.

I'd hate to hear the bad news.

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[rickman]

TTman wrote on 10/17/2017 11:02 AM:

On 17/10/2017 06:30, rickman wrote:
rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and they ask the
buyer to choose between battery types 357090 & 357095. I can't find any
references anywhere that describe what these model numbers mean. Anyone
know?

http://www.ebay.com/itm/201761814378

I've tried asking the vendor but they just keep telling me to read the
description. Any ideas of what these numbers mean?

SNIP
They say that the battery is fully protected internally... over voltage,
undervoltage and over current so should be perfectly safe....

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

"They" say the battery protected, yes. I don't recall anyone assuring that
makes them "perfectly safe". I recall certain cell phones made be a major
manufacturer (with a great deal of reputation at stake) who had a rash of
battery fires while the phone was in people's pockets.

NiMH might be the right way to go. Four Enloop AAs would give 4.8 volts
nominal at around 2000 mAHr and no real circuitry required. Because they
are charged in pairs I've always had trouble keeping them balanced. So my
preference is for the single cell Lithium Polymer if I can make it safe enough.

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

 

[mike]

On 10/17/2017 2:19 PM, rickman wrote:

mike wrote on 10/17/2017 3:07 PM:
On 10/17/2017 3:33 AM, rickman wrote:
Jan Panteltje wrote on 10/17/2017 6:26 AM:
On a sunny day (Tue, 17 Oct 2017 06:18:09 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4lda$4hi$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 5:47 AM:
On a sunny day (Tue, 17 Oct 2017 05:21:15 -0400) it happened rickman
gnuarm@gmail.com> wrote in <os4i2d$cgp$1@dont-email.me>:

Jan Panteltje wrote on 10/17/2017 4:13 AM:
On a sunny day (Tue, 17 Oct 2017 01:30:45 -0400) it happened
rickman
gnuarm@gmail.com> wrote in <os44i7$p0f$1@dont-email.me>:

rickman wrote on 10/16/2017 10:16 AM:
I'm looking at buying these batteries for a test project and
they ask the
buyer to choose between battery types 357090 & 357095. I can't
find any
references anywhere that describe what these model numbers
mean. Anyone know?

http://www.ebay.com/itm/201761814378

It has build in chips to protect it, very unlikely to cath fire if
you use a decent charger chip.

"Very unlikely" is fine when it is sitting on your desk. If that
happens
you get an appropriate fire extinguisher and put it out or at least
let it
burn and put out anything else it has ignited. If you are in a
vehicle
where you have no means of escaping and no way to deal with the
fire, you
are SOL. "Very unlikely" isn't good enough for me.

Na, wrap your nuclear plants in ..


Also, I'm not convinced all of these units have protection. The
two model
numbers would seem to indicate one is 5 mm longer than the other.
I expect
this is exactly the size of the protection board, so one might have
protection and the other might not. It is not all that unusual for
an eBay
listing to contain errors and complete lies^H^H^H^H^H alternate
facts.

True, I only looked at the link, you can see the protection board,
I have some like that, but only 1000 mAh, marked 'Varta'.
From China nevertheless.

I have some without protection board too...more RC type single cell
lipos.
And then I have the 3 cell ones, 30C ... no protection either.
Danger all around me,
Oh and the box with LiIon super powerfull forgot how many C.

Gotta run

Think about it, you find lipos everywhere, even in those blutooth
earplugs /
headsets for your cellphone, and happily plug it in your ear and
wear it on your head.
Cars have gasoline, bad things can happen...
There is a mad dog president in control of the button, I would worry
about that first.
Probabilities.

I seem to recall a number of professional designs from companies who
have
much reputation to loose which burst into flames.

Was it not Liion?



So no, I don't have tons of confidence in Lithium batteries to the
extent
that I want to strap one on my kayak with no physical protection
against the
boat catching on fire.

Well just roll.

I seem to recall Lithium doesn't do so well in contact with water.

Interesting to see how far people will go to ignore the total system
and focus on one ill-conceived component.
The devil is in the details, and we have few.

Not sure what you mean about ignoring the "system"?


Do the math.
How much energy is released in a battery fire?

A lithium batter will release a *lot* more heat than just what is stored
in the battery. Even discharged lithium batteries have to be stored
safely.

Yes, you understand the problem...but what's the number?
I suspect you can't contain a fire in any container you're willing
to paddle around in a kayak. Depends on that number.

If you insulate it, how hot will it get inside, since you've
guaranteed thermal runaway?

Don't care, the concern is to prevent the China syndrome where the
battery burns its case and melts though my boat. High density
polyethylene won't stand up to a lithium fire, or any other type of fire
for that matter.


How much energy is released as heat if you discharge the battery
at maximum current allowed by your current limit strategy?
What does that do to the cell temperature if you insulate it?

The unit won't be drawing the maximum current. There will be protection
to prevent this. The load will be relatively light compared to the C
value. I'm interested in a long discharge time.


How often are you gonna use this kayak device?
Can you not throw it overboard if it catches fire?

Not very easily. It will be securely affixed to the bow of a 17 foot
kayak with me in the middle. My arms aren't 8 foot long.

Ok then that's something you can change in your "system approach".

slight modification of the requirements can make a huge difference in
the "system" solution.

I submit that the release mechanism is far more likely
to jamb than the battery is to catch fire. ;-)

A great reason to prevent a fire from becoming catastrophic.


Given your paranoia, might a NiMH or Alkaline AA cell pack
be more cost effective and weigh less and take up less space
than your protection vault and fire suppression apparatus and floating
burn unit to treat the injured? Maybe you should have two burn
units just in case one of the doctors has a heart attack.

That would be a good idea, but NiMH cells don't have the density. But
that might not be a significant issue.

Looking at the overall system requirements can reveal if this is a viable
option. It does address your major fear. It's all about the weighting
of constraints. Was it the Rolling Stones???You can't always get what you
want..
But the circuits to use NiMH in
> a device like this aren't so common.
Do you care what's common? You building more than one?
If you can accommodate the voltage variation of lithium, you
can probably figger out how to substitute Lithium.

I surmise that there are some devices sold on EBAY that are made
from tested/fully compliant components and do what they say.
Problem is that you can't tell which.

Battery protection built into the battery won't solve your problem.
It's there as a backup to your own carefully crafted redundant
battery management system. I'm not saying you shouldn't have it.
I'm saying that you shouldn't rely on it.

Yes, and the battery charger/step up circuit also incorporates protection.


The good news is that you are very much more likely to drown
than to catch fire.

I'd hate to hear the bad news.