Re: Battery (SLA) modeling

On 13/12/2024 13:31, Don Y wrote:

On 12/13/2024 3:59 AM, Martin Brown wrote:

On 13/12/2024 06:57, 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?

>
Depends what you want to do to the battery for any non-trivial charging or discharging rate you ought to take its temperature into consideration too. I^2R heating with a fudge factor probably a good enough proxy.

>
Yes.  I'm just interested in taking a peek at it at a point in time.
E.g., look at it while under charge (knowing voltage at terminals
and charge current) and then briefly under DIScharge (same observations).
If series resistance is the same, I can infer the potential of the voltage
source from a set of linear equations UNDER THESE CONDITIONS.

 Except for a few special cases, electrode-electrolyte interfaces are
very non-linear and you may find that the potential of the inferred
voltage source is different for charge and discharge conditions.