Electronic battery tester with normal/cold test modes and terminal connection detection

Abstract

An electronic battery tester is disclosed with normal test and cold test modes comprising: a first circuit for applying an AC current load to a battery under test to induce an AC signal across the terminals of the battery; a second circuit for measuring the induced AC signal and converting it to a first voltage potential signal which is a measure of the battery's internal resistance; a circuit for adjusting the first voltage potential signal to a second voltage potential signal; third circuit for generating a threshold voltage potential signal at a first value when the battery tester is in a normal test mode and at a second value when the battery tester is in a cold test mode; and a comparison circuit for comparing said second voltage potential signal to said threshold voltage potential signal to determine a condition of the battery. The battery tester also includes terminal connection detection capability comprising: an indicator driven by an electronic tester unit for indicating a connection when first and second supply leads and first and second return leads are properly connected to the battery under test through corresponding first and second connectors; the electronic tester unit including a circuit governed by the first and second return leads for inhibiting the indicator from indicating a connection when one of the first and second return leads are not properly connected to the negative terminal of the battery under test through the second connector.

Dependencies are inferred from the claim text.