Re: Battery (SLA) modeling

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.

 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)

It might at least near fully charged states or about to be damaged by deep discharge. Manufacturers datasheets are usually helpful.
Not all SLA's are as good as each other for every usage. The ones used in UPS's and invalid buggies seem to be particularly bad & overpriced.
--
Martin Brown