Method and apparatus for testing a vehicle charge storage system

An apparatus for testing a charge storage system in a vehicle, said apparatus comprising:

• a measurement circuit for measuring a terminal voltage of a battery in the vehicle, said circuit providing an output which varies in linear relation to the terminal voltage of the battery within an expected range of voltages, wherein said output is provided only when the terminal voltage of the battery exceeds a threshold level;
• a display circuit for indicating at least one charge storage system operating condition based on the terminal voltage of the battery, said display circuit being electrically connected to the output of the measurement circuit;
• and
• a temperature compensation circuit to compensate for variations in the output due to variations in temperature, said compensation circuit electrically connected to said measurement circuit.

An apparatus for testing a charge storage system in a vehicle, said apparatus comprising:

• a housing;
• a measurement circuit for measuring a terminal voltage of a battery in the vehicle, said measurement circuit being mounted in said housing;
• a display circuit mounted to said housing for indicating at least one charge storage system operating condition based on the terminal voltage of the battery, said display circuit being electrically connected to the output of the measurement circuit;
• and
• a map light mounted to the housing.

An apparatus for testing a charge storage system in a vehicle, said apparatus comprising:

• means for measuring a terminal voltage of a battery in the vehicle, said measuring means providing an output which varies in linear relation to the terminal voltage of the battery within an expected range of voltages, wherein said output is provided only when the terminal voltage of the battery exceeds a threshold level;
• display means for indicating at least one charge storage system operating condition based on the terminal voltage of the battery, said display means being electrically connected to the output of the measuring means;
• and
• output damping means electrically connected to said measuring means for damping variations in said output.

A method for testing a charge storage system in a vehicle, said method comprising:

• electrically connecting a test meter to a battery wherein said test meter includes a display having at least one scale for displaying at least one charge storage system operating condition, a measuring circuit which provides an output that varies in linear relation to a terminal voltage of the battery within an expected range of voltages, wherein said output is provided only when the terminal voltage of the battery exceeds a threshold level, and an output damping circuit electrically connected to said measurement circuit for damping variations in said output;
• measuring the terminal voltage of the battery using said test meter;
• determining at least one charge storage system operating condition based on the terminal voltage of the battery;
• and
• displaying said at least one charge storage system operating condition on said at least one scale.