The typical effective resistance of fresh Energizer® alkaline cylindrical batteries (using a 5 mA
stabilization drain followed by a 505 mA 100 millisecond pulse) will be approximately 150 to 300
milliohms, depending on size.
The effective resistance of a battery will change as the battery is discharged. The drain rate that the
battery is discharged at will effect this change in resistance. Typically, a high drain will result in a
relatively low resistance. Low rate discharges will result in a more gradual increase in resistance
throughout life of the battery. By continually discharging a battery with periodic high current pulses, the
resistance can be calculated through the life of the battery.
The following is an example of an Energizer® AA/LR6 alkaline battery being discharged at 50 mA with 10
mA / 500 mA 1 second pulses every 12 minutes. The brown line indicates the voltage discharge curve.
The orange dashes are the calculated resistance (delta volts ÷ delta current) which corresponds to the
secondary Y axis on the right hand side of the graph (fig. 10).