Abstract: A battery state determining apparatus is provided which can accurately determine a state of a lead battery in an automotive vehicle. The apparatus calculates a corrected engine starting voltage Vst1 from an open-circuit voltage (OCV) measuring section that measures the open circuit voltage Vst of the lead battery at an engine starting time in accordance with a temperature of the vehicle. The apparatus further calculates a battery determination voltage Vst_th representing a voltage of the lead battery at an engine starting time when a growth rate of internal resistance of the lead battery reaches a predetermined value from the open-circuit voltage OCV. The apparatus then determines the battery state of the lead battery by determining whether the corrected engine starting voltage Vst1 is larger than the battery determination voltage Vst_th and whether the corrected engine starting voltage Vst1 belongs to a predetermined region on a characteristic map.

Abstract: A battery state judging method is provided capable of properly judging a state of a lead-acid battery by measuring voltages without measuring currents. A state of the battery is judged by obtaining, in advance, a DC internal resistance r0 of a same type battery in a new and fully-charged state; calculating, in advance, a load R [R=r0×Vst0/(OCV0?Vst0)] at an engine starting time (S112) from an open-circuit voltage OCV0 (S104) and a lowest voltage Vst0 (S108) at the engine starting time, both measured when the loaded battery is in a new and fully-charged state, and the DC internal resistance r0; calculating a DC internal resistance r [(r=R/(OCV?Vst)/Vst)] of the loaded battery from an open-circuit voltage OCV (S104) and a lowest voltage Vst (S108), both measured when the loaded battery is in a deteriorated/insufficiently-charged state, and the load R; and comparing r and r0.

Abstract: A storage battery unit (1) including a storage battery (2) and a monitoring device (3) that monitors a state of the storage battery using an output of the storage battery as an input, wherein, in order to prevent the monitoring device from consuming electric power in a state before use of the storage battery and prevent nonfunctioning of the monitoring device in use of the storage battery, a starting circuit (4) is provided between the storage battery and the monitoring device (3), the starting circuit including: a main switch that holds an OFF state in a state before a load is connected to the storage battery and interrupts supply of electric power from the storage battery (2) to the monitoring device; and a switch drive circuit that detects a reduction in terminal voltage of the storage battery that occurs when the load exceeding the set value is connected to the storage battery, and sets the main switch to an ON state.

Abstract: A battery state judging method is provided capable of properly judging a state of a lead-acid battery by measuring voltages without measuring currents. A state of the battery is judged by obtaining, in advance, a DC internal resistance r0 of a same type battery in a new and fully-charged state; calculating, in advance, a load R [R=r0×Vst0/(OCV0?Vst0)] at an engine starting time (S112) from an open-circuit voltage OCV0 (S104) and a lowest voltage Vst0 (S108) at the engine starting time, both measured when the loaded battery is in a new and fully-charged state, and the DC internal resistance r0; calculating a DC internal resistance r [(r=R/(OCV?Vst)/Vst)] of the loaded battery from an open-circuit voltage OCV (S104) and a lowest voltage Vst (S108), both measured when the loaded battery is in a deteriorated/insufficiently-charged state, and the load R; and comparing r and r0.

Abstract: The present invention provides a battery state determining apparatus which can determine a battery state of a lead battery from an engine starting voltage accurately considering influence of a temperature of a vehicle. An engine starting voltage Vst1 obtained by correcting an engine starting voltage Vst of a lead battery at an engine starting time is calculated based upon an open-circuit voltage OCV and a temperature of a vehicle (S112), a battery determination voltage Vst_th representing a voltage of the lead battery at an engine starting time when a growth rate of internal resistance of the lead battery reaches a predetermined value from the open-circuit voltage OCV is calculated (S126), and a battery state of the lead battery is determined by determining whether an engine starting voltage Vst1 belongs to a predetermined region on a characteristic map (S132).

Abstract: A storage battery unit (1) including a storage battery (2) and a monitoring device (3) that monitors a state of the storage battery using an output of the storage battery as an input, wherein, in order to prevent the monitoring device from consuming electric power in a state before use of the storage battery and prevent nonfunctioning of the monitoring device in use of the storage battery, a starting circuit (4) is provided between the storage battery and the monitoring device (3), the starting circuit including: a main switch that holds an OFF state in a state before a load is connected to the storage battery and interrupts supply of electric power from the storage battery (2) to the monitoring device; and a switch drive circuit that detects a reduction in terminal voltage of the storage battery that occurs when the load exceeding the set value is connected to the storage battery, and sets the main switch to an ON state.