Path: ...!news-out.netnews.com!postmaster.netnews.com!us1.netnews.com!not-for-mail
X-Trace: DXC=`fTD?4J?lGiO7B^IE@GQfnU5[F2hIijDo7J470dMQQ7kAUDUcSnb?@iE_MTfRQdZnmZ:CMO0P>2odW@E8<O<J]3`63^FDd_VWmgR<@>HgL4:V`_[?n`d5S`@e
X-Complaints-To: support@frugalusenet.com
Date: Tue, 17 Dec 2024 00:25:21 -0500
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: Battery (SLA) modeling
Newsgroups: sci.electronics.design
References: <vjgltr$394qj$1@dont-email.me>
 <82roljdcepbps2or1vlqq3ll0qnkhvgadm@4ax.com> <vjiolr$3mpt5$1@dont-email.me>
Content-Language: en-US
From: bitrex <user@example.net>
In-Reply-To: <vjiolr$3mpt5$1@dont-email.me>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Lines: 33
Message-ID: <67610b17$0$1783$882e4bbb@reader.netnews.com>
NNTP-Posting-Host: 127.0.0.1
X-Trace: 1734413079 reader.netnews.com 1783 127.0.0.1:40933
Bytes: 2205

On 12/13/2024 8:57 PM, Bill Sloman wrote:
> 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.
> 

I guess not many universities offer a PhD in non-physical chemistry 
these days. :(