does overcharging _lithium_ batteries release _hydrogen_?...

D

danny burstein

Guest
My first thought is nope, but...

[NY Post]

Number of fatalities from NYC fires jumped 16 percent in 2021, data shows
....
The FDNY noted that four of the fire deaths in 2021 - including one in the East
Village - resulted from blazes sparked by the lithium ion batteries in stored
ebikes/scooters.
....
Fire officials warn that when the batteries are damaged or overcharged, they
release hydrogen gas and can explode.
======
rest:
https://nypost.com/2022/01/08/number-of-fire-fatalities-in-nyc-jumped-16-percent-in-2021/

Thanks...
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]
 
Short answer is: Not under typical conditions and/or with a correct charger.. However:

The electrolytes are flammable, and lithium itself is highly flammable. So, if the battery is overcharged and starts to leak, the released materials can cause fires and release a great deal of energy. Or if the battery is physically damaged such as a cracked casing or similar.

Peter WIeck
Melrose Park, PA
 
On Sun, 9 Jan 2022 13:40:39 +0000, danny burstein <dannyb@panix.com>
wrote:

My first thought is nope, but...

[NY Post]

Number of fatalities from NYC fires jumped 16 percent in 2021, data shows
....
The FDNY noted that four of the fire deaths in 2021 - including one in the East
Village - resulted from blazes sparked by the lithium ion batteries in stored
ebikes/scooters.
....
Fire officials warn that when the batteries are damaged or overcharged, they
release hydrogen gas and can explode.
======
rest:
https://nypost.com/2022/01/08/number-of-fire-fatalities-in-nyc-jumped-16-percent-in-2021/

Thanks...
Click to expand...

\"Explosion Hazards from Lithium-Ion Battery Vent Gas\"
<https://www.osti.gov/servlets/purl/1574807>
These gases build within the cell and can ultimately
lead to rupture of the cell and release of the gases.
The gas mixture generated and released is flammable,
consisting of various mixtures of hydrogen, carbon-monoxide,
carbon-dioxide and various hydrocarbons including methane
and propane. Ignition of these gases result in fire
and explosion scenarios that pose a significant risk to
surrounding life and property.

The article goes on to detail which gasses are produced, under what
conditions, and in what proportions, which changes depending on SOC
(state of charge).

--
Jeff Liebermann jeffl@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
 
danny burstein wrote:
=================
My first thought is nope, but...


Number of fatalities from NYC fires jumped 16 percent in 2021, data shows
....
The FDNY noted that four of the fire deaths in 2021 - including one in the East
Village - resulted from blazes sparked by the lithium ion batteries in stored
ebikes/scooters.
....
Fire officials warn that when the batteries are damaged or overcharged, they
release hydrogen gas and can explode.
Click to expand...

** Think that is not the most likely scenario.

If ( whatever) gas leaks out under pressure, the cell is the unlikely to explode.
That\'s why many rechargeable cells have vents built in - NiCd, NiMh and alkalines too.
SLAs often have no vents and will explode( spraying acid) if over charged at a high enough rates.
Strangely, NiCds will too, if charged under freezing conditions.

The most likely *fire hazard* is damage - when there is a short in the wiring or from one cell body to another.
The huge current that flows in the next few minutes will cause massive heating and set any flammable plastic involved alight.
Then nearby carpets, and furnishings clothing etc.

Lithium Ion ( LiPo ) cells are worse hazards that older types cos of the much greater energy storage per cell.
The advice to have your eBike sited outdoors when charging is very wise.

...... Phil
 
In <q23ntg5lrilplci9dfa0tk0qabhpjjbp21@4ax.com> Jeff Liebermann <jeffl@cruzio.com> writes:

[lots snipped]

\"Explosion Hazards from Lithium-Ion Battery Vent Gas\"
https://www.osti.gov/servlets/purl/1574807

The article goes on to detail which gasses are produced, under what
conditions, and in what proportions, which changes depending on SOC
(state of charge).
Click to expand...

Thanks. That article (which, despite coming through Elseveir,
is a freebie) is *exactly* the background info I was looking for.

So they seem to agree with me. In a residential setting with
a couple of e-bike batteries, the fire risk is almost entirely
from \"thermal runaway\" and not gas production/escape.

Thanks again.


--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]
 
On Mon, 10 Jan 2022 05:27:26 -0000 (UTC), danny burstein
<dannyb@panix.com> wrote:

In <q23ntg5lrilplci9dfa0tk0qabhpjjbp21@4ax.com> Jeff Liebermann <jeffl@cruzio.com> writes:

[lots snipped]

\"Explosion Hazards from Lithium-Ion Battery Vent Gas\"
https://www.osti.gov/servlets/purl/1574807

The article goes on to detail which gasses are produced, under what
conditions, and in what proportions, which changes depending on SOC
(state of charge).

Thanks. That article (which, despite coming through Elseveir,
is a freebie) is *exactly* the background info I was looking for.
Click to expand...

OSTI (US governmint office of scientific and techy info) apparently
contracted with Elseveir to handle their distribution. I forgot to
mumble something about the article search:
<https://www.osti.gov>
They have 23,135 articles listed under \"lithium ion battery safety\"
keyword search:
<https://www.osti.gov/search/semantic:lithium%20ion%20battery%20safety>
or 147 under the exact phrase:
<https://www.osti.gov/search/semantic:%22lithium%20ion%20battery%20safety%22>
The first article found is rather interesting:
\"Materials for lithium-ion battery safety\"
<https://www.osti.gov/servlets/purl/1475493>
This Review aims to summarize the fundamentals of
the origins of LIB safety issues and highlight recent
key progress in materials design to improve LIB safety.

So they seem to agree with me. In a residential setting with
a couple of e-bike batteries, the fire risk is almost entirely
from \"thermal runaway\" and not gas production/escape.
Click to expand...

In my never humble opinion, the more likely eBike scenario is
mechanical damage, either from modifying or soldering the battery pack
cells, or having the eBike crash into something. Also included are
high resistance contacts causing the safety fuse to fail to trip, BMS
(battery management system) misprogramming or miswiring, and various
attempts to convince the eBike to deliver more power. Locally, I\'ve
only seen 3 eBike fires and have been told about 3 others. All were
the result of owner tampering, shoddy repair, cell replacement, or
combinations of these. A commercial eBike system is probably fairly
safe. A do-it-thyself mess of mods and repairs is probably not so
safe.

Hint: Store your batteries in a fireproof box, preferably with a
working smoke alarm nearby:
\"Underrated E-Bike Battery Fire Hazards Call for Attention on Safe
Storage\"
<https://www.bike-eu.com/home/nieuws/2018/02/underrated-e-bike-battery-fire-hazards-call-for-attention-on-safe-storage-10132804>
Methinks things will be better when the cobalt cathode are replace
with LiFePO4 cells.

--
Jeff Liebermann jeffl@cruzio.com
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
 
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