US 2012/0072144 A1 · METHOD AND APPARATUS FOR ESTIMATING SOC OF A BATTERY

Abstract

A method of determining a state-of-charge for a battery is provided. A startup state-of-charge of the battery is determined as a function of a present open circuit voltage measurement for a present ignition startup, at least one open circuit voltage observation of a previous ignition startup, and a current draw integration over a time period from a previous ignition startup event to a present ignition startup event. A run state-of-charge change of the battery is determined for an ignition key-on operation. The run state-of-charge change comprises a difference between the present open circuit voltage measurement and the at least one previous open circuit voltage observation, and is determined in response to of a current draw integration over a respective period of time. The state-of-charge of the battery is calculated based on a function of the startup state-of-charge and the run state-of-charge change of the battery.

Claims20

Dependent claims

A method of determining a state-of-charge for a battery, the method comprising the steps of:

measuring open circuit voltages of a vehicle battery during ignition startups;
determining a startup state-of-charge of the battery as a function of a present open circuit voltage measurement for a present ignition startup, at least one open circuit voltage observation of a previous ignition startup, and a current draw integration over a time period from a previous ignition startup event to a present ignition startup event;
determining a run state-of-charge change of the battery for an ignition key-on operation, the run state-of-charge change comprising a difference between the present open circuit voltage measurement and the at least one previous open circuit voltage observation, and determined in response to a current draw integration over a respective period of time;
and
calculating the state-of-charge of the battery based on a function of the startup state-of-charge and the run state-of-charge change of the battery.

2 more elements

A system for determining a state-of-charge of a battery comprising:

a battery;
at least one component for drawing power from the battery;
a voltmeter for measuring an open circuit voltage of the battery at ignition start sequences;
a current sensor for sensing current drawn from the battery;
and
a control module for determining a state-of-charge of a battery as a function of the startup state-of-charge and the run state-of-charge change of the battery, the startup state-of-charge being determined at a time of an ignition startup event, the startup state-of-charge being a function of a present open circuit voltage measurement for a present ignition startup, at least one previous open circuit voltage observation, and a current integration over time period from a previous ignition event to a present ignition event, the run state-of-charge change comprising at a time during an ignition on operation, the run state-of-charge change being estimated as a difference between the present open circuit voltage measurement and at least one previous open circuit voltage observation determined in response to current integration over a respective period of time.

3 more elements

Dependencies are inferred from the claim text.

Method and apparatus for estimating soc of a battery

Life of this patent

Method and apparatus for estimating soc of a battery

Life of this patent

Abstract

Claims20