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From: Bill Sloman <bill.sloman@ieee.org>
Newsgroups: sci.electronics.design
Subject: Re: Battery (SLA) modeling
Date: Sat, 14 Dec 2024 12:57:04 +1100
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On 14/12/2024 4:23 am, john larkin wrote:
> On Thu, 12 Dec 2024 23:57:54 -0700, Don Y
> <blockedofcourse@foo.invalid> wrote:
> 
>> At a fixed time and temperature, is it safe to model a battery as a
>> fixed voltage source behind a series resistance?  Possibly, additionally,
>> a parallel RC to cover transients?
>>
>> In particular, does the model need to change based on whether the
>> battery is being charged or discharged?  (i.e., to estimate that
>> series resistance)
> 
> I've wondered about electro-chemical time lags, ions drifting around
> in liquids, as in what would the Spice model of some battery be?

That's what Warburg impedances are about.

> And
> on a slower time scale, the morphology of a battery changes with time.
> Nearly discharged batteries sure go Hi-Z.
> 
> What we need here is a good physical chemistry guy.

I've got a Ph.D. in physical chemistry, but batteries are 
electrochemistry - I know a guy who has just completed a Ph.D. with a 
thesis on a particular lithium ion battery chemistry. It's a specialised 
subject.

-- 
Bill Sloman, Sydney