Abstract: The condition of a storage battery of an internal combustion engine powered vehicle is tested automatically, and an indication of battery condition is provided to the service technician. The battery testing apparatus is connected to the positive (+) and negative (-) terminals of the battery to measure battery voltage under several different conditions. In particular, the battery testing apparatus measures battery voltage under open circuit conditions, while subjecting the battery to a predetermined AC load, and while subjecting the battery to a predetermined DC load. The battery testing apparatus also includes a temperature probe which measures the temperature of the battery.

Abstract: A system and method for testing a battery having an internal impedance by generating digital battery parameter values corresponding to the battery parameters at different points in time by means of current, voltage and temperature measurement circuits and an analog-to-digital converter. An electrical load is periodically placed on the battery and the battery is also charged between loadings in order to provide battery parameter values during different battery conditions. A microprocessor coordinates the testing of the battery and the measuring of the battery parameter values, as well as the calculation of test criteria based on those values in order to quickly and accurately analyze the condition of the battery.

Abstract: A system for measuring the state of charge of a storage battery is disclosed which corrects charging and discharge electrical quantities of the battery in view of temperature and charging efficiency of the battery, and the like to precisely measure the state of charge thereof by digital-operation. There is also disclosed a system correcting, by digital-operation, the variation in capacity of the battery due to the variation in life of the battery and/or the self-discharge thereof as well, to thereby measure the state of charge with higher precision.

Abstract: There are described apparatus for measuring the temperature of the electrolyte material in a lead-acid storage battery without physical access to that material. The apparatus is included as a part of a larger apparatus for analyzing the condition of the battery and its suitability for further use in automobile lighting, starting, and ignition applications. The apparatus measures the temperature of a brass connector placed in thermal contact with the battery negative post at a time immediately prior to connecting the analyzing apparatus to the battery and at a predetermined time thereafter and produces an output signal indicative of the electrolyte temperature in response to those measurements.