JP2927354B2 - Battery charging method and charging device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a battery charging method and a charging device for performing quick charging.

[Background of the Invention]

Conventionally, a rapid charging device to which a constant current charging control device and a -ΔV full charge detection control device are added has a problem in operability because some operation such as turning on a power switch is required to start charging. .

[Object of the invention]

The object of the present invention is to eliminate the above-mentioned disadvantages of the prior art,
It is to improve operability.

[Summary of the Invention]

The present invention detects that a battery set is connected to a charging device by detecting a terminal voltage of a temperature sensing element, and starts charging when the connected battery set is a chargeable battery set that is not at a high temperature. If the battery set is a battery set that should not be charged at a high temperature, charging is not started, and charging is automatically started when the temperature of the battery set falls below a predetermined value.

(Example of the invention)

FIG. 1 is a circuit diagram showing one embodiment of the present invention, and FIGS. 2 to 4 are flowcharts for explaining the operation of the present invention. In the figure, 1 is an AC power supply, 2 is a transformer, 3, 4, 9, 10
Is a diode, 5 and 6 are SCRs constituting the switching element of the present invention, and perform constant current charging control and charging stop control.
Reference numeral 7 denotes a battery set including a plurality of batteries 7a and a thermostat 7b which is provided in proximity to at least one of the batteries 7a and is thermally affected by the battery 7a and opens its contact when the battery 7a reaches a predetermined temperature. Is a constant voltage power supply comprising a diode 11a, a smoothing capacitor 11b, and a three-terminal voltage regulator 11c, and serves as a power supply for a single-chip microcomputer (to be referred to as a microcomputer hereinafter) 12 and an operational amplifier 16a to be described later. 12 is arithmetic means (CPU)
12a, ROM 12b, RAM 12c, timer 12d, A / D converter 12e,
The microcomputer is composed of an external interrupt input port 12f, an input port 12g, and an output port 12h. The RAM 12c stores the charging current data Inew obtained through the A / D converter 12e, the battery voltage data Vnew, and the battery voltage data Vol processed by the arithmetic unit 12a.
d, peak battery voltage data Vpeak, voltage drop data ΔV
And so on. Timer 12d starts operating when the power supply voltage is zero volts, and after the timer set time elapses, SCR5, 6
Handle the interrupt of the firing control of.

Numeral 13 denotes a power supply zero-cross detecting means comprising a transistor 13a and resistors 13b and 13c. When the power supply voltage is zero volt, an interrupt signal is generated at an external interrupt input port 12f of the microcomputer 12. 14 is a transistor 14a, a diode 14b, a resistor
A thermostat status signal generating means consisting of 14c, 14d and 14e.
Generates a state signal. The thermostat state signal generating means 14 outputs a signal indicating a closed state of the thermostat 7b when the battery set 7 is connected to a charging device 18 described later, and a thermostat when the battery set 7 is removed from the charging device 18 or when the battery is fully charged.
It generates a signal indicating that the thermostat 7b is open when the thermostat 7b operates, and constitutes a battery assembly connection detecting means together with the thermostat 7b. That is, when the battery set 7 is connected to the charging device 18, if the battery set 7 is not at a high temperature and the contacts of the thermostat 7b are closed, the terminal voltage of the thermostat 7b, that is, the potential of the connection point of the resistors 14c and 14d is set to the ground potential. Therefore, the transistor 14a is turned off, and the thermostat state signal generating means 14 sends a state signal of logical value 1 to the input port 12g of the microcomputer 12. On the other hand, battery set 7 is thermostat at high temperature
If the contact of 7b is open, the terminal voltage of the thermostat 7b is the voltage (Vbe + (5-Vbe) * determined by the base-emitter voltage (Vbe) of the transistor 14a and the resistors 14c (R14c) and 14d (R14d). R14d / (R14c + R14d)), the transistor 14a is turned on, and the thermostat state signal generating means 14 sends a state signal of logical value 0 to the input port 12g of the microcomputer 12. If the battery set 7 is not connected, the state is the same as the state in which the thermostat 7b is opened, and a state signal having a logical value 0 is sent to the microcomputer 12 as described above.

Therefore, the microcomputer 12 can detect and judge the connection of the battery set 7 including the state of the thermostat 7b, and the connected battery set 7 should not be charged at a high temperature.
It is possible to detect and determine whether or not the battery set 7 can be charged at a high temperature. Reference numeral 15 denotes a battery voltage detecting means composed of resistors 15a and 15b, which divides the battery voltage of the battery set 7 to obtain the A / D
Input to converter 12e. 16 is operational amplifier 16a, resistor 16
The output of the current detecting means 8 is smoothed to a DC voltage by integrating means comprising b, 16c and a capacitor 16d. 17 is a transistor
This is an SCR firing means consisting of 17a, diode 17b, and resistors 17c and 17d. 18 is the above transistor 2, diode 3,
4, 9, 10, SCR5, 6, current detection means 8, constant voltage power supply 1
1, a charging device comprising a microcomputer 12, a power supply zero-cross detecting means 13, a thermostat state signal generating means 14, a battery voltage detecting means 15, an integrating means 16 and an SCR firing means 17.

Next, the operation will be described with reference to the flowcharts of FIGS. When the battery set 7 is connected to the charging device 18 and the arithmetic means 12a determines that the thermostat 7b is closed via the thermostat state signal generating means 14 → input port 12g (step 103), the microcomputer 12 turns off the power supply to zero-cross. Enable the external interrupt from the detection means 13 (step 10
4) Start charging with constant current control (steps 201 to 205)
And full charge detection control (step 301). Battery pack 7
When is connected to the charging device 18, when the battery set 7 becomes hot immediately after discharging a large current and the thermostat 7b is in the open state, the process returns to step 103 again to determine whether the thermostat 7b is in the closed state. This loop is repeated until the thermostat 7b is closed. Thermostat 7b
When is closed, the process proceeds to step 104 to start charging.

The constant current charge control is performed by the current detection means 8 → A / D converter 1
The timer set time (ignition time of SCR5 and SCR6) is calculated based on the difference between the data Inew obtained through 2e and the charging current setting data Iref previously written in the ROM 12b, and the charging current to the battery 7a is calculated. Is controlled to be constant. That is, In
When ew and Iref are equal, the timer setting time is kept as it is, and the conduction angle of SCR5, 6 is not changed. When Inew is smaller than Iref, the timer setting time is reduced to increase the conduction angle of SCR5, 6 (step 204). . Conversely, when Inew is larger than Iref, the timer set time is increased, the conduction angle of SCRs 5 and 6 is reduced (step 205), and control is performed so that the charging current to battery 7a becomes Iref.

After the full charge detection control, the detection is performed by detecting whether the thermostat 7b is opened during charging. That is, the state of the thermostat 7b is monitored by the calculating means 12a. When the thermostat 7b is in the closed state, the charging is continued. When the thermostat 7b is in the interposed state, the external interrupt is prohibited (step 303) and the charging is performed. It stops and determines whether the battery voltage data Vnew is zero (step 305). When the battery voltage Vnew is not zero, the steps 304 and 305 are repeated assuming that the battery set 7 remains connected to the charging device 18, that is, the fully charged battery set 7 is not removed. When the battery voltage Vnew is zero, it is determined that the battery set 7 has been removed from the charging device 18,
The process returns to step 103 to wait for the next battery set 7 to be charged.

If the battery pack 7 is removed from the charging device 18 during charging,
The microcomputer 12 determines from the signal from the thermostat state signal generating means 14 that the thermostat 7b is in the open state (Step 301), and prohibits the external interrupt (Step 3).
03) Stop charging, determine that the battery voltage data Vnew is zero (step 305), and wait for the next battery set 7 to be charged.

Here, the microcomputer 12 sets a timer set time by an external interrupt from the power supply zero-cross detecting means 13 as shown in FIGS. 3 and 4 (step 401), and integrates the charging current data into the current detecting means 8 → integration. Means 16 → input via A / D converter 12e, store in Inew data area of RAM 12c (step 403), and input battery voltage data via battery voltage detection means 15 → A / D converter 12e, and Vnew
The data is stored in the data area (step 404). On the other hand, in the case of the timer interrupt of the internal timer 12d, the firing control of SCRs 5 and 6 is performed (steps 501 to 504).

FIG. 5 is a flowchart showing another embodiment of the present invention. The operations of charging start, constant current charging control, and charging stop are the same as those in FIGS. Here,-△ V fully charged electrode control will be described (steps 601 to 610).

In the-△ V full charge detection control, when the peak value flag is reset (when the battery voltage does not reach the peak), the data Vnew newly obtained through the A / D converter 12e is larger than the data Vold previously input. At this time, the Vnew data is written to the Vold data area of the RAM 12c (step 604), and is compared again with the next new data. When charging is near full charge, Vn
There is a point where ew is smaller than Vold.

At this time, the peak value flag is set (step 60).
5) Set Vold as the peak voltage data Vpeak (step 60)
6). Further, the charging continues and the battery voltage drops. When the battery voltage drops by-△ V from the peak voltage Vpeak, the external interrupt is prohibited (step 608), the charging is stopped, and the state of the thermostat 7b is monitored (step 609). When it is determined that the battery set 7 has been removed from the charging device 18 and the thermostat 7b has been opened, the peak value flag is reset (step 610), and the battery pack 7 waits for charging.

〔The invention's effect〕

As described above, according to the present invention, charging is automatically started only by connecting a battery set, so that an operation of turning on a power switch is not required, and operability can be improved. In addition, when the battery set connected to the charging device is at a high temperature, charging is automatically started when the battery set cools and drops to a predetermined temperature, even if the battery set remains connected, so that operability is improved. Further improve.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram showing an embodiment of the present invention.
4 are flow charts for explaining the operation of the present invention, FIG.
FIG. 11 is a flowchart showing another embodiment of the present invention. In the figure, 5 and 6 are SCRs, 7 is a battery set, 7a is a battery, 7b
Is a thermostat, 8 is charging current detecting means, 12 is a microcomputer, 12a is arithmetic means (CPU), 12b is ROM, 12c is RAM, 12d
Is a timer, 12e is an A / D converter, 12f is an interrupt input port, 12g is an input port, 12h is an output port, 14 is a thermostat state determining means, 15 is a battery voltage detecting means, and 17 is an SC.
The R ignition means 18 is a charging device.

Continuation of the front page (56) References JP-A-61-109428 (JP, A) JP-A-58-49048 (JP, A) JP-A-61-7226 (JP, U) JP-A-61-96742 (JP) , U)

Claims (3)

(57) [Claims] 1. A battery charging method comprising: starting charging when a battery set including a battery and a temperature-sensitive element provided in the vicinity of the battery is connected; and charging the connected battery set. The connection of the battery set to the charging device is detected by detecting the terminal voltage of the temperature-sensitive element. If the connected battery set is a rechargeable battery set that is not at a high temperature, charging is started. A method of charging a battery, wherein charging is not started in the case of a battery set that should not be charged in step (1), and charging is automatically started when the temperature of the battery set falls below a predetermined value. 2. A charging device for charging a battery set comprising a plurality of batteries connected in series and a thermostat provided near at least one of the batteries and opening a contact when a battery temperature is equal to or higher than a predetermined value. A switching element provided between a battery set connected to a power supply, and connection of the battery set to a charging device is detected by detecting a terminal voltage of the thermostat and detecting an open / closed state of the thermostat to connect the battery set. Battery connection detection control means for turning on the switching element to start charging when the battery pack is detected, and when the battery connection detection control means detects connection of a rechargeable battery set at a high temperature, that is, a closed state of the thermostat. When the switching element is turned on to start charging and battery connection detection control means detects connection of a battery group that should not be charged at a high temperature. That is, when detecting the open state of the thermostat, charging is not started without turning on the switching element, and charging is automatically started when the temperature of the battery set falls below a predetermined value, that is, when the closed state of the thermostat is detected. A battery charging device characterized in that: 3. A charging device for charging a battery set including a plurality of batteries connected in series and a temperature-sensitive element provided in the vicinity of at least one of the batteries, wherein the battery set is connected to a charging power source. The connection between the switching element and the battery set is detected by detecting the terminal voltage of the temperature sensing element. When the connection of the battery set is detected, the switching element is turned on to start charging. Battery connection detection control means for causing the battery pack connection detection control means to turn on the switching element to start charging when detecting connection of a rechargeable battery set without high temperature, When detecting connection of a battery group that should not be charged at high temperature, charging is not started without turning on the switching element, and charging is automatically started when the temperature of the battery group falls below a predetermined value. A battery charging device characterized in that the battery is charged.