Storage battery condition indicator with temperature and load current compensation

Claim 1

A DEVICE FOR INDICATING THE CONDITION OF A STORAGE BATTERY WHICH SUPPLIES CURRENT TO A LOAD, SAID DEVICE INCLUDING A COMBINATION, FIRST AND SECOND CONDUCTORS ADAPTED TO BE CONNECTED RESPECTIVELY TO THE POSITIVE AND NEGATIVE TERMINALS OF THE BATTERY, FIRST RESISTANCE MEANS CONNECTABLE IN SERIES BETWEEN THE STORAGE BATTERY AND THE LOAD, TRANSISTOR MEANS COUPLED TO SAID FIRST RESISTANCE MEANS AND HAVING AN OUTPUT CURRENT RESPONSIVE TO CHANGES IN POTENTIAL ACROSS SAID FIRST RESISTANCE MEANS, SECOND RESISTANCE MEANS COUPLED TO SAID TRANSISTOR MEANS SO THAT THE DROP IN POTENTIAL THEREACROSS IS RESPONSIVE TO THE OUTPUT CURRENT OF SAID TRANSISTOR MEANS, AND A VOLTMETER AND A ZENER DIODE CONNECTED BETWEEN SAID FIRST AND SECOND CONDUCTORS IN SERIES WITH SAID SECOND RESISTANCE MEANS, SAID VOLTAGE ACROSS SAID SECOND RESISTANCE MEANS COMPENSATING SAID VOLTMETER FOR THE VARIATION IN POTENTIAL ACROSS THE STORAGE BATTERY PRODUCED BY FLUCTUATING LOAD CURRENT FLOW, WHEREBY SAID VOLTMETER WILL ONLY BE INFLUENCED BY VARIATIONS IN POTENTIALS ACROSS THE STORAGE BATTERY DUE TO CHANGES IN THE CONDITION THEREOF.