A battery as a source is often represented by its O/C voltage in series with its internal resistance. When it is being charged can it be represented in the same manner with the same IR or does the internal resistance change when it is being charged??

 

Hi Malcolm Sanders

If the battery is half loaded, has a lower impedance* than when it is fully charged.

So the impedance* changes as you go charging.

But if it is loaded by means of a current regulator. that is another roll.

* internal resistance

 

The battery apparent internal resistance does change some with the state of charge, going down as the charge goes up, but is basically the same whether it is being charged or discharged (for a given state of charge).

 

A simplistic model of a lead-acid battery during charge is shown in my recent post here.