How can the E4980A or the 4263B measure internal impedance of batteries?

Insert DC blocking capacitors between the Hcur terminal and a battery and between the Hpot terminal and a battery as shown in the figure below.

The 16065C External Bias Adapter (50 Hz to 1 MHz) can substitute for the DC blocking capacitors because it contains the capacitors as shown in the figure below. Internal impedance of a battery can be measured by connecting the E4980A or 4263B LCR Meter, the 16065C, and appropriate test leads (such as the 16089A/B/D/E) as shown in the figure.

Note: The DC blocking capacitors cause measurement errors at low frequencies. It is recommended to perform Open/Short/Load compensation at the ends (clips) of the test leads in order to minimize measurement errors at low frequencies below 1 kHz.

Note: A basic method for measuring batteries with an LCR Meter is described in Section 5.11 on page 5-31 of the Impedance Measurement Handbook (5950-3000).