equvivalent circuit of dc batteries

[mehuldanger@gmail.com]

i want to know that does DC BATTRIES HAVE INTERNAL INDUCTANCE AND CAPACITANCE ALSO? LIKE INTERNL RESISTANCE?

 

[betwixt]

Yes.

Inductance in the connection between the cell and it's contacts (very small).
Internal resistance which varies with cell type, state of charge and age.

For most applications you can model them as a perfect voltage source with a resistor in series to represent the ESR. If you need a more accurate model you would have to take into account the chemistry of the battery type and it's ability to convert chemical into electrical energy. Obviously that calculation is much more complicated and depends on the cell manufacture.

Brian.

 

[mehuldanger@gmail.com]

brian sir i want to know one thing why battery hasparacitic capacitance and due to ehat reson paracitic capacitance exsist??

 

[chuckey]

Because the battery is two plates suspended in some sort of chemical. There will be capacitance between the plates and inductance as the current flows along the plates.
Frank

 

[mehuldanger@gmail.com]

but capacitance is what we know two conducting plates seperated by dielectric and in battery we have electrolyte in between two plates and electrolyte is conductor

 

[csolis_GT]

Two things that you may consider:

1) batteries has limited capacity, so at some extend the capacitance can model how the voltage changes when the charge in storage is decreasing.

2) I am not to sure about this one, but the charge has to go through chemical reactions and that take times. Maybe, that effect (if noticeable) can also be modeled by a capacitance. This would be similar as the transition capacitance when a diode is forward biased.

 

[FvM]

Capacitance of the popular battery models is physically located in the double layer between electrodes and electrolyte, bypassed by a resistive impedance component.

It should be noted that these RLC models are small signal models with varying parameters, describing the batter yimpedance for a particular charge state.