State detecting system and device employing the same

#The present invention relates to a novel state detecting device for detecting states such as charge condition, residual capacity in a power storage means such as a lithium secondary battery, a nickel hydride battery, a lead seal battery, an electric double layer capacitor, and to a power source unit, a distribution type power storage device, and an electric vehicle which use the state detecting device.

#In a power source unit, a distribution type power storage device and an electric vehicle employing power storage means, such as a battery, a state detecting device is employed for detecting state of the power storage means in order to safely and effectively use the power storage means. The state of the power storage means represents state of charge (hereinafter abbreviated as “SOC” indicative how much charged or how much dischargeable charge amount resides, residual capacity, or state of health (hereinafter abbreviated as “SOH”) indicative of how much exhausted or weakened or degree of deterioration.

#The SOC in the power source unit of a portable equipment, an electric vehicle and so forth can be detected by integrating a discharge current from a fully charged state and calculating a ratio of a charge amount residing in the power storage means (hereinafter referred to as “residual capacity”) versus a maximum chargeable charge amount (hereinafter referred to as “full capacity). However, many power storage means varies the full capacities depending upon SOH, temperature and so forth, it is difficult to accurately detect SOC with respect to secular change and variation of environment.

#The present invention will be understood more fully from the detailed description given hereinafter and from the accompanying drawings of the preferred embodiment of the present invention, which, however, should not be taken to be limitative to the invention, but are for explanation and understanding only.

#FIG. 1 is a constructional illustration of a power source unit according to the present invention;

#FIG. 2 is a block diagram sowing a calculation process of the power source unit according to the present invention;

#The present invention will be discussed hereinafter in detail in terms of the preferred embodiment of the present invention with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be obvious, however, to those skilled in the art that the present invention may be practiced without these specific details. In other instance, well-known structures are not shown in detail in order to avoid unnecessary obscurity of the present invention.

#(First Embodiment)

#FIG. 1 is a constructional illustration of a power source unit according to the present invention. In FIG. 1, the reference numeral 101 denotes power storage means, 102 denotes measuring means, 103 denotes storage means, 104 denotes arithmetic means, 105 denotes communication means, 106 denotes first correction means and 107 denotes second correction means. The power storage means 101 is formed with a device having a power storage function, such as a lithium secondary battery, a nickel hydride battery, a lead seal battery, an electric double layer capacitor and so forth.