Re: OT: Kids got an E-scooter?

On 25/06/2024 12:48 am, john larkin wrote:

On Sun, 23 Jun 2024 12:51:30 -0700, wmartin <wwm@wwmartin.net> wrote:
 

On 6/23/24 09:56, Cursitor Doom wrote:

On Sun, 23 Jun 2024 11:25:21 +1000, Bill Sloman wrote:
>

On 23/06/2024 9:58 am, john larkin wrote:

On Sat, 22 Jun 2024 22:39:48 +0100, TTman <kraken.sankey@gmail.com>
wrote

On 22/06/2024 18:22, Cursitor Doom wrote:

On Sat, 22 Jun 2024 09:12:04 -0700, john larkin wrote:

On Sat, 22 Jun 2024 13:22:25 +0100, Cursitor Doom
<cd@notformail.com>
wrote:

<snip>

 From what I've read, most lithium battery explosions happen when the
batteries are idle, neither charging nor discharging, basically
connected to nothing.

The problem here is that your reading comprehension isn't great.

The times from normal to smoking to exploded is
seconds.

The cells may look perfectly normal in visible light, but what you are talking about is thermal runaway.
With lithium batteries, the cells have to get up to between 140 to 160 Celcius before the process can take off. That's hot.
With a charged battery there is always some self-discharge, and that does warm the battery some extent, and it gets worse as the cells get old. The processes that contribute to self-discharge move faster when the cells are warm, so you get more self-discharge in old batteries (but bad charging habits don't help either). They have to be very far gone before they can run away.
Any kind of properly designed battery monitoring system should give you plenty of early warning, and should be able to discharge the battery (if slowly) before they get to be dangerous. It's a design problem, and not one you seem to be able to think about.
--
Bill Sloman, Sydney
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