초록 ▼

A state of charge gauge for measuring the state of charge of secondary batteries, such as the type employed in electric vehicles, includes a microprocessor which, when supplied with data varying in accordance with battery discharge current and battery terminal voltage, determines battery resistance.

A state of charge gauge for measuring the state of charge of secondary batteries, such as the type employed in electric vehicles, includes a microprocessor which, when supplied with data varying in accordance with battery discharge current and battery terminal voltage, determines battery resistance. Having determined battery resistance which is a dynamically varying parameter dependent on battery temperature and age, the microprocessor computes the total battery charge capacity. Comparison of the quantity of battery charge already depleted with the previously computed total battery charge capacity yields an accurate indication of remaining battery charge.

대표청구항 ▼

A state of charge indicator for measuring the state of charge of secondary batteries and for providing a visual indication of remaining battery charge comprising: a data circuit adapted to be coupled to a secondary battery under load for providing first and second output signals proportional to the

A state of charge indicator for measuring the state of charge of secondary batteries and for providing a visual indication of remaining battery charge comprising: a data circuit adapted to be coupled to a secondary battery under load for providing first and second output signals proportional to the magnitude of battery discharge current and battery terminal voltage, respectively; processing means coupled to said data circuit for computing battery dynamic resistance in accordance with the magnitude of battery discharge current and the magnitude of battery terminal voltage and for computing total battery charge capacity in accordance with battery dynamic resistance and battery charge already delivered and determining the remaining battery charge by comparing total battery charge capacity with battery charge already delivered; and display apparatus coupled to said processor unit for providing a visual indication of remaining battery charge determined by said processor unit.