Automatic battery tester with recording means for battery performance

Claim 1

An automatic battery discharger and recorder comprising in combination: a. a circuit including a plurality of fixed resistors, b. manual means connected with said fixed resistors for selecting at least one of said resistors and connecting it in said circuit to form a base resistance, c. a variable resistor connected in said circuit in series with said fixed resistors, said base resistance and said variable resistance together comprising a load resistance through which a battery is discharged, d. means in said circuit for selecting a desired current rate for a battery, e. current monitor means in said circuit for comparing the current discharge rate of the battery with the desired selected current rate, f. servo means in said circuit responsive to a difference in said battery current discharge rate and the selected current rate as detected by said current monitor means and operable to adjust said variable resistor whereby the actual discharge current equals the selected current, g. recorder means in said circuit to record the time, voltage and current of discharge, h. voltage dropout means including sensing means for comparing the instantaneous battery voltage with a preselected dropout voltage and for sensing the value of the combined load resistance, said dropout means operable to trip a voltage relay when the battery voltage equals the selected voltage and the load resistance is insufficient for the test to automatically terminate a test until a different base resistance is selected from said fixed resistors to render said load resistance sufficient for the test, and i. means to adjust the voltage value at which said voltage dropout means is operable.