JP2012080619A - Charger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that there is a case where a charged battery is very hot when it is grasped just after charging is completed since it is over-charged as a charge battery and a battery temperature becomes high in such a state, when a charger employs a system for detecting the drop of battery voltage in a charging end-stage.SOLUTION: The charger includes: a voltage area dividing portion dividing the voltage of each charge battery into a plurality of voltage areas in accordance with the voltage of the charge battery, which is detected by a voltage detecting portion of a power supply portion at prescribed timing; and a temperature area dividing portion detecting the temperature change of the battery during charging from a temperature conversion element arranged near the charge battery and dividing the temperature into a plurality of temperature areas. The charger also includes a determining portion for operating a full charge display portion by delaying prescribed time when the voltage and the temperature by the voltage area dividing portion and the temperature area dividing portion reach prescribed areas.

Description

  The present invention relates to a charger that detects the voltage and temperature of a rechargeable battery when charging a plurality of rechargeable batteries individually, and displays full charge after lowering the battery temperature when charging is completed.

  In recent years, nickel-metal hydride batteries that can be reused when charged in the same shape as a typical AA or AAA are increasing. Many chargers for charging the rechargeable battery are also provided. Many of these chargers perform charge control by a method of detecting a drop in battery voltage at the end of charge or a method using a charge timer (see, for example, Patent Document 1).

  On the other hand, a temperature differential detection type charging device that completes charging by mounting a thermistor and making a determination by calculating the temperature of the rechargeable battery and the amount of temperature increase per unit time has been proposed.

  For example, charging of the charging battery is completed by a temperature detecting means for detecting the temperature of the charging battery in the charging device, a temperature differential detecting means for obtaining a temperature differential value that is a temperature increase amount per unit time of the detected temperature, It has been proposed to reduce the risk of heat generation and prevent misjudgment of full charge.

Japanese Patent Laid-Open No. 2001-210387

  In the case of a method for detecting a drop in battery voltage at the end of charging as in Patent Document 1, the rechargeable battery is overcharged, the battery temperature becomes high in that state, and the charged battery is held immediately after completion of charging. And is very hot. In addition, since this charging method is overcharged, the cycle deterioration of the rechargeable battery is accelerated.

  The present invention solves the conventional problems as described above, prevents overcharging of the rechargeable battery, and monitors the temperature of the rechargeable battery to display a full charge so that it does not feel hot even when touching the rechargeable battery. An object of the present invention is to provide a charger.

  In order to achieve the above object, the present invention provides a control unit that controls power and voltage supplied to a rechargeable battery while controlling power and voltage supplied to the rechargeable battery according to the power supplied to the rechargeable battery. A charging battery mounting unit for mounting the charging battery, a voltage detection unit for detecting the charging voltage of the charging battery, a temperature detection unit for detecting the temperature of the charging battery, and a voltage at the end of charging of the charging battery by the voltage detection unit In a charger including a full charge display unit that detects a drop and displays a full charge after a predetermined delay after the detection, according to the voltage of the rechargeable battery detected at a certain timing by the voltage detection unit A voltage area dividing unit for dividing the voltage of each rechargeable battery into a plurality of voltage areas, and a temperature conversion element provided in the vicinity of the rechargeable battery to detect a temperature change of the battery being charged, and A temperature area dividing unit that divides into the rear, and the voltage and temperature generated by the voltage area dividing unit and the temperature area dividing unit reach a predetermined area, so that the full charge display unit is activated with a predetermined time delay. This is a charger characterized by providing a portion.

  According to the present invention, in a battery charger equipped with a temperature monitoring function, even if the battery is in contact with the rechargeable battery immediately after the battery is fully charged, it feels hot because the battery temperature is controlled in a certain temperature area. Is almost gone. In addition, the battery cycle deterioration can be suppressed due to the control that does not easily cause overcharge.

The block diagram of the charger which shows one embodiment of this invention Explanatory drawing which shows schematic structure of the charger of one embodiment of this invention Outline flowchart of voltage area division processing Outline flowchart of temperature area division processing Outline flow chart of charging completion judgment Schematic of charging completion area Charging voltage and battery temperature waveform diagram to which the present invention corresponds

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram of a charger according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram illustrating a state in which a plurality of rechargeable batteries according to an embodiment of the present invention are connected to the charger.

  In FIG. 2, reference numeral 1 denotes a charger main body for a rechargeable battery. The rechargeable battery 3 is charged by attaching the rechargeable battery 3 to the rechargeable battery attachment portion 6 of the charger main body 1. At this time, the charge control circuit 2 determines the number of the rechargeable batteries 3 to be attached, and if attached, performs charge control on the rechargeable batteries 3 that are attached.

  In addition, the charging state of the mounted rechargeable battery 3 is indicated by a combination of lighting, blinking, and extinguishing of the full charge display unit 4 made of LEDs.

  The charging method of the connected rechargeable battery 3 in the first embodiment will be described in detail with reference to FIG. The charger main body 1 has a space for mounting the rechargeable battery 3, the rechargeable battery 3 is mounted, and the outlet plug 5 provided in the charger main body 1 is connected to a household outlet.

  As a result, the charge control circuit 2 operates, and charging control is performed on the mounted rechargeable battery 3 by detecting in which space the rechargeable battery 3 is mounted and determining the voltage and temperature of the battery.

  FIG. 1 is a block diagram of a charger including the charging control circuit 2 in FIG. In FIG. 1, reference numeral 7 denotes a power supply unit, which comprises a circuit including an outlet plug 5 that receives power supplied from an outlet.

  The power source unit 7 is connected to an output control unit 9 including a plurality of switching elements via a current control unit 8, and the rechargeable battery 3 is connected to the output side of the output control unit 9.

  A plurality of temperature detection elements 10 constituting a temperature detection unit such as a thermistor are arranged in the vicinity of the rechargeable battery 3, and the temperature detection elements 10 are connected to the temperature detection unit 11. The temperature detector 11 is connected to a temperature area divider 12 that divides temperature information detected by the rechargeable battery 3 into a plurality of temperature areas.

  Further, a voltage input switching unit 13 is connected to the rechargeable battery 3, and the voltage input switching unit 13 is connected to a voltage detecting unit 14, so that the voltage detecting unit 14 detects the voltage of each charging battery 3 at a constant timing. It has become.

  Information on the voltage of the rechargeable battery 3 detected by the voltage detection unit 14 is configured to be sent to a voltage area dividing unit 15 that divides the voltage into a plurality of voltage areas according to the magnitude of the voltage.

  When each temperature and voltage of the rechargeable battery 3 in the temperature area dividing unit 12 and the voltage area dividing unit 15 reach a predetermined area, the determination unit 16 sends a signal to the control unit 17 and is connected to the control unit 17. The full charge display unit 4 is operated by delaying a predetermined time by the count unit 18.

  The temperature detection unit 11, the temperature area division unit 12, the voltage detection unit 14, the voltage area division unit 15, the determination unit 16, the control unit 17, and the time count unit 18 are configured by one microcomputer 19.

  A simple operation of FIG. 1 will be described. When the outlet plug 5 arranged in the charger main body 1 is connected to a household outlet, the power is turned on and charging is started.

  When the power is turned on, the mounted charging control microcomputer 19 operates. The control unit 17 provided in the microcomputer 19 determines whether or not the rechargeable battery 3 is attached to the rechargeable battery attachment unit 6 and performs a series of charge control when the rechargeable battery 3 is attached.

  First, a battery voltage is input to determine the presence or absence of a battery. While the voltage input switching unit 13 is controlled to sequentially switch each charging battery 3, each charging battery 3 is switched from the voltage detection unit 14. Input the voltage. It is determined whether or not the rechargeable battery 3 is attached based on the input voltage. This battery voltage is input periodically to monitor battery attachment / detachment. When it is determined that the appropriate rechargeable battery 3 is mounted by the battery voltage input, the connected rechargeable battery is controlled by controlling the current controller 8 and the output controller 9 from the controller 17 in the microcomputer 19. 3 is charged.

  When charging of the rechargeable battery 3 is started, the voltage detector 14 periodically monitors the voltage of the rechargeable battery 3 and the temperature detecting element 10 monitors the temperature of the rechargeable battery 3. Similarly, the battery detector 14 monitors the presence or absence of a voltage drop at the end of charging.

  While the rechargeable battery 3 is being charged, the time counting unit 18 counts how long the rechargeable battery 3 is being charged. If this count exceeds the maximum charging time, the control unit 17 ends the charging for safety.

  A series of charging control is performed in which the state of charging as described above is displayed by turning on, blinking, and turning off the LED of the full charge display unit 4.

  In this way, by performing charging control that combines the detection of the battery voltage drop -ΔV at the end of charging and the time count monitoring, the charging battery 3 is prevented from being insufficiently charged or overcharged. It has the effect that charging becomes possible.

  Normally, when the charging battery 3 is normally charged as shown in the charging voltage waveform of FIG. 7, the control is performed by setting the charging time determined by the charging battery 3, and the battery charging end stage that appears in the vicinity of that time. The charging control is such that the charging is completed by detecting the battery voltage drop -ΔV. At this time, the rechargeable battery 3 is overcharged, and the temperature of the rechargeable battery 3 becomes high in the vicinity of -ΔV detection. Therefore, the user may feel very hot when removing the battery to be used immediately after full charge.

  Such a situation needs to be avoided since it may cause a problem in terms of safety and battery life. Moreover, since the maximum charging time is set, safety problems can be suppressed, but an overcharged state of the rechargeable battery 3 is inevitable.

  Also in Patent Document 1, the flow of control is completed by -ΔV determination of the battery voltage drop at the end of battery charging.

  In the present invention, when charging a plurality of individual rechargeable batteries 3, the voltage and temperature of the rechargeable battery 3 as shown in the schematic flowcharts of FIGS. 3, 4, and 5 are divided into a plurality of areas. Safe charging control without overcharging is performed so that the charging waveform in each charging battery 3 is completed as much as possible before −ΔV.

  A schematic flowchart and operation of the voltage area dividing process of FIG. 3 will be described. Each rechargeable battery 3 is charged at a fixed timing. For example, when four rechargeable batteries 3 are mounted on the rechargeable battery mounting portion 6, the timing of charging is controlled by the microcomputer 19 in the order of 1, 2, 3, 4, 1, 2,. As shown in the flowchart of FIG. 3, the first rechargeable battery 3 detects a voltage when another rechargeable battery 3 is being charged, and is divided into a plurality of voltage areas depending on the magnitude of the detected voltage. The In FIG. 3, when the detected voltage is 1.51 V or more, the voltage area is 3, when the detected voltage is 1.50 V or more, the voltage area is 2, and when the detected voltage is 1.49 V or more, the voltage area is 1. Below 1.49V, the voltage area is set to zero. In this example, it is divided into four stages.

  Operationally, the voltage input switching unit 13 in FIG. 1 switches the charging order of the rechargeable batteries 3, the voltage detecting unit 14 detects the voltage, and the voltage area dividing unit 15 further divides the voltage area.

  Next, a schematic flowchart and operation of the temperature area dividing process of FIG. 4 will be described. This also detects temperature information from each temperature detection element 10 at a fixed timing. For example, when two thermistors are arranged, temperature information is detected in the order of 1, 2, 1, 2,. As shown in the flowchart of FIG. 4, the chargeable temperature is divided into a plurality of temperature areas based on the detected temperature information. In FIG. 4, when the detected temperature is 50 ° C. or higher, the temperature area is set to 2, when the detected temperature is 30 ° C. or higher, the temperature area is set to 1, and when the detected temperature is lower than 30 ° C., the temperature area is set to 0. In this example, it is divided into three stages.

  In operation, the temperature information from the temperature detection element 10 in FIG. 1 is detected by the temperature detection unit 11, and the temperature area division unit 12 further divides the temperature area.

  Based on the divided area information as shown in the flowcharts of FIGS. 3 and 4, the charging completion determination is performed as shown in the flowchart of FIG.

  In FIG. 5, the charging completion determination is performed based on the divided area information as shown in FIGS. The shaded portion shown in the example of FIG. 6 is a charging completion area. Completion determination is performed by the determination unit 16 in FIG.

  When entering the charging completion area in FIG. 5, since the actual battery temperature has not risen to the peak, the full charging display unit 4 immediately displays the charging completion. In addition, even if the charging completion area is not reached, if charging is completed at -ΔV, the temperature may become high. By setting a delay at that time, the actual charging operation is completed, but the battery is fully charged. Control is performed to wait for the temperature of the rechargeable battery 3 to be lowered by continuing the charge display on the display unit 4.

  As shown in the examples of the flowcharts of FIGS. 3, 4, and 5 above, charging is completed by detecting -ΔV while detecting the voltage and temperature of the rechargeable battery 3 connected to the charger body 1 at a certain timing. Therefore, it is possible to control the full charge display unit 4 to perform charging without worrying about the user who has suppressed the battery temperature.

  Further, as shown in the example of FIG. 6, the charging battery 3 has a temperature characteristic such that charging in a low temperature atmosphere hardly increases the voltage of the charging battery, and charging in a high temperature atmosphere has a lower voltage than in the low temperature. Therefore, it is possible to complete the charging immediately before −ΔV by dividing the charging completion area in more detail. In this case, even if the full charge display unit 4 immediately displays the completion, the battery temperature is not so high so that the user does not feel uneasy.

  However, since there are various types of batteries, in the case of -ΔV detection, the batteries still become hot.

  In order to avoid this state, in the present invention, when -ΔV is detected at a high temperature, the full charge display unit 4 controls the charge continuation display to continue charging, and the charging is completed when the battery temperature decreases.

  By doing so, overcharging can be suppressed, and charging with a low battery temperature can be achieved.

  The charger according to the present invention is a charger equipped with a temperature detection element such as a thermistor. When charging a plurality of rechargeable batteries, the number of connected rechargeable batteries and the number of charged batteries is monitored, When charging is completed at a high temperature such as −ΔV, the control can be performed such that the charging display is continued for a certain period of time and the battery temperature is lowered, thereby reducing anxiety that the battery is hot when charging is completed.

DESCRIPTION OF SYMBOLS 1 Charger main body 2 Charging control circuit 3 Rechargeable battery 4 Fully charged display part 5 Outlet plug 6 Rechargeable battery mounting part 7 Power supply part 8 Current control part 9 Output control part 10 Temperature detection element 11 Temperature detection part 12 Temperature area division part 13 Voltage Input switching unit 14 Voltage detection unit 15 Voltage area division unit 16 Determination unit 17 Control unit 18 Time counting unit 19 Microcomputer

Claims (1)

  A control unit for controlling power and voltage supplied to the rechargeable battery and controlling power and power supplied to the rechargeable battery by connecting to the power supply unit, a rechargeable battery mounting unit for mounting the rechargeable battery, A voltage detector that detects the charging voltage of the rechargeable battery, a temperature detector that similarly detects the temperature of the rechargeable battery, and the voltage detector detects a voltage drop at the end of charging of the rechargeable battery. In a charger having a full charge display unit that displays a full charge at a delay time, a plurality of voltages of each charging battery are set according to the voltage of the charging battery detected at a certain timing by the voltage detection unit. A voltage area dividing unit that divides the battery into voltage areas, and a temperature area dividing unit that detects a temperature change of the battery being charged from a temperature conversion element provided in the vicinity of the charging battery and divides the battery into a plurality of temperature areas. The charging is provided with a determination unit that activates the full charge display unit with a predetermined time delay when the voltage and temperature by the voltage area dividing unit and the temperature area dividing unit reach a predetermined area. vessel.

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