Patent ID: 7996165

Claim:
A portable measurement device for determining a parameter of a battery comprising: a first contactor to connect to a first terminal of the battery, the first contactor comprising a first pair of leads; a second contactor to connect to a second terminal of the battery, the second contactor comprising a second pair of leads; a housing configured to house a measurement circuit, the measurement circuit comprising: a switch to selectively connect a resistive load to the battery via one of the first pair of leads and one of the second pair of leads; an analog to digital (AD) converter connected to the battery via another one of the first pair of leads and another one of the second pair of leads, and wherein the AD converter is configured to: receive a first voltage from the battery before the resistive load is connected to the battery and convert the first voltage to a first digital signal; receive a second voltage from the battery after the resistive load is connected to the battery and convert the second voltage to a second digital signal; and receive a third voltage from the battery after the resistive load is disconnected from the battery and convert the third voltage to a third digital signal; a microcontroller configured to: calculate voltage drop data as a function of the first, second, and third digital signals; retrieve voltage profile data corresponding to a voltage drop profile for a desired parameter from a memory; and compare the voltage drop data to the voltage profile data to determine a value of the desired parameter; and a display to generate the value of the desired parameter for display.