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From: ehsjr <ehsjr@verizon.net>
Newsgroups: sci.electronics.design
Subject: Re: Battery (SLA) modeling
Date: Fri, 13 Dec 2024 18:20:22 -0500
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On 12/13/2024 1:57 AM, Don Y 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)
> 

For what value of "safe"?

Probably better, in general, to use manufacturer's
discharge curve, at least as a starting point. If
your application differs appreciably from the test
conditions in the manufacturers specs, you need to
test it yourself, again depending on what you have
in mind by "safe".

It's better to design the system to accommodate the
battery at its best and worst SOC/capacity levels.
Also the age of the battery and how it has been
treated over that age is a factor, so take that
into account too.

Ed