The Effect of Wire-Path Resistance on Battery Measurements (.PDF Download)

Proper wiring and probing/contacting are critical to making successful measurements. When testing cells or batteries, using good engineering practices is important to avoid noise pickup, signal degradation, and unwanted voltage drops through wiring and contact resistances.

If you’re testing cells or batteries at high currents, resistance will be a critical consideration. As test currents rise, the resistance in the wires and in the contacts will cause significant voltage drops.

Wire-Path Resistance Voltage Drops are Problematic During Battery Discharge

These voltage drops can cause problems during the discharge of a battery into an electronic load, as electronic loads have a minimum operating voltage. Note when I say electronic load, this could be a benchtop electronic load or the discharge circuits in a battery tester (sometimes called a battery cycler). As the battery voltage drops during discharge, the battery voltage may approach the minimum operating voltage of the electronic load.