KR0152367B1 - Rapid charger without imperfect charging - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge completion detector reset circuit of a quick charger, and more particularly, to an apparatus for removing an incomplete charge completion phenomenon of an inactivated battery, which frequently occurs in a fast charger of a battery. That is, the conventional technique for eliminating the initial incomplete charge completion phenomenon of the inactivated battery is to operate the charge completion detection circuit after a fixed pre-charge time irrespective of the remaining charge of the battery to deactivate the fully discharged battery Although the above phenomenon could not be completely eliminated by operating the detector in a state in which the preliminary charging time was not sufficiently activated, the present invention operates the detector after an appropriate precharging time according to the remaining charge of the battery, thereby increasing the full charging efficiency. In addition, when the battery is fully charged, the detector operates without precharging, so the risk of overcharge can be reduced, which is very useful.

Description

Rapid Charger Eliminates Incomplete Charging

1 is a graph of voltage change with time showing the discharge characteristics of the battery.

2 is a block diagram of a conventional battery fast charger.

3 is a block diagram illustrating the configuration of a fast charger in which the incomplete charging phenomenon of the present invention is eliminated.

* Explanation of symbols for main parts of the drawings

1: charging circuit 2: discharge circuit

3: battery 4: control circuit

5: Charge completed detector 6: Charge remaining detector

7: latch circuit 8: mux

9: timer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge completion detector reset circuit of a quick charger, and more particularly, to an apparatus for removing an incomplete charge completion phenomenon of an inactivated battery, which frequently occurs in a fast charger of a battery.

There are two main methods of resetting the charged detector installed in the rapid charger, one of which is operated about 5 minutes after the battery starts charging, and the other is charged by setting an arbitrary reference voltage. Only when the battery voltage is higher than the reference voltage, the charge completion detector operates.

In the above method, the former method does not activate the deactivated battery during the charging time of about 5 minutes, and thus, the incomplete charge completion phenomenon frequently occurs due to the detector operation, and when the preliminary charging time is increased, it is fully charged. If the battery is fully charged, there is a risk of overcharging.

The latter method is inconvenient to set the reference voltage according to each situation because the charge voltage of the battery is very different depending on the type of battery, capacity and external environment (temperature).

Referring to the drawings in detail, FIG. 1 is a graph of voltage variation with time showing the discharge characteristics of a battery. The discharge rate is 1C at 25 ° C. and X is used to represent a discharge state of a battery having 4 cells. The axis shows the passage of time, one unit is 5 minutes (5 min / DIV), and the Y axis is the voltage change, and one unit is 1 V (1 V / DIV).

2 is a block diagram of a conventional battery rapid charger, which includes a charging circuit 1, a discharge circuit 2, a battery 3, a control circuit 4, and a charge completion detector 5. As shown in FIG.

In the conventional fast charger configured as described above, when the battery 3 is mounted in the charger, the discharge circuit 2 operates to discharge the battery completely or discharge the battery 1 at a predetermined current for a predetermined time. Operate to charge. At this time, the charge completion detector 5 is operated after precharge for about 5 minutes, regardless of the remaining charge of the battery.

Therefore, since the inactivated battery cannot be activated with a charging time of about 5 minutes, the incomplete charging completion phenomenon occurs frequently. At this time, if the precharge time was increased, there was a risk of overcharging when the battery was fully charged.

The present invention is to solve the above conventional problems, characterized in that by determining the discharge state of the battery, and optionally controls the precharge time.

When described in detail with reference to the drawings, the block diagram of the configuration of the fast charger to remove the incomplete charging phenomenon of the present invention can be shown as shown in FIG.

In a rapid charger comprising a charging circuit 1, a discharge circuit 2, a battery 3, a control circuit 4, and a charge completion detector 5; The charge remaining detector 6 for detecting the remaining charge of the battery 3, the latch circuits 10 and 11 for maintaining the charged remaining state detected by the charged remaining detector 6, and the battery 3 A mux 8 for setting a precharge time according to the state of charge remaining, a timer 9, and a latch circuit 7 for maintaining a set time state.

In the fast charger according to the present invention configured as described above, when the battery 3 is attached to the charger, the discharge circuit 2 operates to discharge at a predetermined current (usually 1C in 5 minutes) for a predetermined time and then discharge. Calculate the remaining charge of the battery (3). At this time, the precharge time for operating the charge completion detector 5 is changed according to the calculated remaining charge amount, that is, when the discharge voltage is 1.1V or less per cell (full discharge state) during discharge, the precharge time is sufficiently long (full charge). 70% of the time), and when the discharge voltage is 1.2V or more per cell, the preliminary layer discharge time is set short (about 10% of the total charge time).

Therefore, the conventional method, that is, has a sufficiently long precharge time on average than the method of operating the charge completion detector after about 5 minutes of pre-layer charge time irrespective of the remaining charge of the battery, due to the deactivation of the battery during the initial charge The filling completion phenomenon can be eliminated.

When the battery 3 is mounted in the charger, the control circuit 4 first drives the discharge circuit 2 to generate an arbitrary current (current of about 1 minute in about 5 minutes) in order to calculate the remaining charge of the battery 3. Discharge.

When the battery 3 is discharged, the control circuit 4 operates the remaining charge detection circuit 6 and the timer 9 immediately before driving the charging circuit 1 to check the discharge voltage to determine the remaining charge state. (Full discharge, intermediate state, sufficient charge state), and the mux 8 is controlled to set the preliminary charge time with the timer 9. When the precharge time is set, the control circuit 4 immediately operates the charging circuit 1 to charge the battery 3 and the control circuit 4 after the precharge time set by the timer 9 and the mux 8. During operation, the charge completion detector 5 is controlled.

That is, when the battery discharge voltage is 1.1V or less per cell, the output of the charge remaining detection circuit becomes 1, 0. When the battery discharge voltage is between 1.1V and 1.2V per cell, the output of the charge remaining detection circuit is 0, respectively. When the battery discharge voltage is 1.2V or more per cell, the output of the charge remaining detection circuit becomes 0 and 1, respectively. This is shown in Table 1 for clarity.

As described above, the technique for eliminating the initial incomplete charge completion phenomenon of the inactivated battery is to deactivate the fully discharged battery by operating the charge completion detection circuit after a fixed precharge time irrespective of the remaining charge of the battery. In this case, the precharging time is short and the detector is not fully activated, so the above phenomenon cannot be completely eliminated. However, in the present invention, the detector is operated after an appropriate precharging time according to the remaining charge of the battery. In the case of a fully charged battery, since the detector operates without precharging, the risk of overcharging can be reduced, which is very useful.

Claims (1)

In a rapid charger comprising a charging circuit 1, a discharge circuit 2, a battery 3, a control circuit 4, and a charge completion detector 5; The precharge time is set according to the charge remaining amount detector 6 for detecting the remaining charge level of the battery 3 and the remaining charge level of the battery 3 detected by the charged amount remaining detector 6, i.e. When the precharge time is discharged, if the discharge voltage in full discharge state is 1.1V or less per cell, set the precharge time long enough to 70% of the total charge time, and if the discharge voltage is 1.2V or more per cell, The precharge time is shortened to about 10%, and the mux 8, latch circuits 7, 10, and 11, and a timer are set to set 30% of the total charge time between 1.1V and 1.2V. Rapid charger removing the incomplete charging phenomenon, characterized in that it comprises a (9).