JPH09215216A - Charger for charging a plurality of batteries in parallel with each other - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contract charging times of respective batteries, by adopting a two-stage charging method using a provided rectifier with a large current capacity and a plurality of provided rectifiers with respective small current capacities, and by performing the chargings of the respective batteries by the rectifier with a large current capacity while switching the rectifier time-divisionally to the respective batteries. SOLUTION: Providing in a charger 2 a rectifier 5 with a large current capacity, rectifiers 9, 10, 11 with respective small current capacities, switchover circuits 6, 7, 8 and a charging sensor 12, first, a battery 13 is connected with the rectifier 5 by the switchover circuit 6 to perform a large-current charging. Then, when one of the voltage, temperature rise and gassing generation of the battery 13 or their composite value reaches a preset value, on the basis of the signal of the charging sensor 12, the connection of the battery 13 is switched from the rectifier 5 to the rectifier 9 by the switchover circuit 6 to connect simultaneously a battery 14 with the rectifier 5 by the switchover circuit 7. The switchovers performed when the state values of the batteries 14, 15 reach their respective preset values are executed by similar methods. Still, the chargings by the rectifiers 9, 10, 11 are completed respectively after respective preset lapses of time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of storage battery parallel charging devices for simultaneously charging a plurality of storage batteries.

[0002]

2. Description of the Related Art In a conventional charger, when charging a plurality of storage batteries, it is usual to charge one storage battery with one charger. However, recently, in order to reduce the installation area of the charger, a method of charging a plurality of storage batteries by providing an output switching circuit in one charger has been proposed, as in JP-A-61-273134. .

[0003]

As described above, by charging a plurality of storage batteries with one charger, there is an advantage that the installation area of the charger can be reduced and the usage rate of the charger can be increased. However, if the charging of one storage battery is completed and then the charging of the next storage battery is started, the charging time is a multiple of the charging time of one storage battery.

For example, assuming that one storage battery is charged for 8 hours, it takes 16 hours to complete two storage batteries, and it may not be in time when the battery is used at night for the next morning. Further, in the case of charging one storage battery with one charger, there is a defect that a large power supply capacity is required if a plurality of storage batteries are charged at the same time. Further, leaving the battery for a long time after charging after discharging has a drawback that it has a bad influence on the life, especially in the case of a lead battery.

[0005]

The present invention adopts a two-step charging current system which is used for charging an ordinary storage battery in order to eliminate these drawbacks, and is divided into a large current rectifier and a small current rectifier. It was decided to charge multiple storage batteries with a charger built into one.

The set value of the current varies depending on the type of the storage battery, the ambient temperature, and the like. As an example, first, a current with a 1-hour discharge rate of the nominal capacity is charged by a large-current rectifier to obtain the temperature and gas. When a specified value is reached by detection of occurrence, voltage rise, etc., the 20-hour discharge rate current is switched to be charged by a small-current rectifier for 8 hours, during which the large-current rectifier charges the next storage battery. By doing so, the charging time is shortened.

For example, the charging time of two 100 Ah storage batteries will be roughly estimated.

In the conventional method, if the battery is charged at a rate of 100 A per hour until the specified voltage is reached and the charged amount is about 80% of the capacity, it means that 80 Ah is charged for 0.8 hours. Next, at a discharge rate of 20 hours and a current of 5 A, the capacity of 12
Charged with a small current rectifier up to 0% (normal efficiency to 1% capacity)
It takes 8 hours to charge to 20%), so it takes 8.8 hours to fully charge one storage battery. 2
If you continue to charge the second unit, you will need double the charging time of 17.6 hours.

On the other hand, when the method of the present invention is used, 1
Charge the first battery with a high-current rectifier for 0.8 hours, then charge it with a small-current rectifier for 8 hours, and after the first battery's high-current charging is complete, charge the second battery's high-current with That is, the time for the first storage battery to be fully charged is 8.8 hours, and the time for the second storage battery to be fully charged is only 0.8 hours delayed from the first storage battery. Can be completed.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of the present invention. In a charger that receives electric power from a three-phase or single-phase AC power source 1 to charge a plurality of storage batteries in a two-stage current charging system, Alternatively, the charger 2 supplied with electric power from the single-phase AC power source 1 passes through the circuit breaker 3 and the transformer 4, and then the high-current rectifier 5
To the charging terminals through switching circuits 6, 7 and 8, and the transformer 4 to the small current rectifiers 9, 10 and.
11 is a switching circuit 6, in parallel with the rectifier 5.
It is connected to the charging terminal through 7 and 8. The switching circuits 6, 7, and 8 receive information on the storage battery, for example, charging voltage, storage battery temperature, presence or absence of gassing, and when the preset value is reached, the rectifier 5 causes the rectifiers 9, 10 and 11 to operate. It is characterized in that it is configured to connect a charge detector 12 which gives a switching signal to each and charge the storage batteries 13, 14, 15 connected to the charging terminals.

The operation of this device is as follows.

Charging is started by turning on the circuit breaker 3 in the charger 2 connected to the three-phase or single-phase AC power source 1, and the voltage is reduced to a required voltage by the transformer 4 and rectified into a direct current by the rectifier 5. Then, the storage battery 13 is charged through the switching circuit 6. The other storage batteries are not charged at this point. Since the rectifier 5 is charged with a large current, the voltage, temperature rise, or gassing preset by the charge detector 12 is reached in a short time, and when any of these or a combined setting is reached, A circuit is configured so that a signal is supplied to the switching circuit 6 and switching is performed so that the rectifier 9 charges the storage battery, and at the same time, a signal is also supplied to the switching circuit 7 so that the storage battery 14 can be charged from the rectifier 5 through the switching circuit 7. Next, as with the storage battery 13, the storage battery 14 is also switched by the charge detector 12 at the time when it detects that the preset value has been reached, and the switching circuit 7 is switched to charge from the rectifier 10.
At the same time, the charge detector 12 also provides a signal to the switching circuit 8 so that the storage battery 15 can be charged from the rectifier 5 through the switching circuit 8. This is repeated for the charger terminals. If the storage battery is not connected to the charging terminal, the charging detector 12 can detect it, for example, by detecting that nothing is connected to the charging terminal or no current flows, and the charging terminal 12 is detected. The charge detector 12 is provided with a function of charging the battery by skipping it to the next storage battery without being connected to the rectifier.

After the small current rectifiers 9, 10 and 11 have started charging, they are charged for a predetermined time and then stopped and the charging is completed. In this case, an end lamp (not shown) or the like is displayed.

FIG. 2 shows the charging status at this time. Assuming that a time T for flowing a large current and a time t for flowing a small current are t hours, for example, the time required to charge three storage batteries is 3 when charging all series batteries.
(T + t) time.

According to the charging method shown in FIG. 2 according to the present invention, the time required to charge three storage batteries is (3T +
t) time, which is shortened by 2t time.

Another method for further shortening the charging time of a plurality of batteries will be described with reference to FIG.

This is a method of charging each storage battery in a pulsed manner by time division, instead of continuously supplying a large current to one storage battery. The time for one pulse to flow a large current is
It can be freely selected within the range of several milliseconds to several tens of minutes, and the pulse width can be changed at the beginning and the end so that efficient charging can be performed. However, in the case of pulse charging, the time of continuous flow to one storage battery is changed depending on the number of pulses. That is, the charge detector 12 outputs a signal so that a pulsed current (in the case of pulse charging, a pulse group) from the large-current rectifier 5 is sequentially supplied to each storage battery. Between the current of the pulse, if the current is made to flow with the small current rectifier,
Further, the charging time is shortened, and the shorter the pulse width of the plurality of storage batteries, the smaller the difference between the charging completion times of the storage batteries.

The charging time with a large current is the same as that in the previous embodiment, but the charging time with a small current after the completion of charging with a large current can be set shorter than in the previous embodiment.

[0020]

According to the present invention, one large-current rectifier 5 is provided, and then a small-current rectifier is provided for each charging terminal in one charger, which is inexpensive, shortens the charging time, and reduces the charging time. The installation area of the battery can be reduced, and the capacity of the power supply can be significantly reduced as compared with charging a plurality of storage batteries with a plurality of chargers.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of the present invention.

FIG. 2 is a timing chart showing a charge state according to an embodiment of the present invention.

FIG. 3 is a timing chart showing a state of charge according to a second embodiment of the present invention.

[Explanation of symbols]

1 ... Three-phase or single-phase AC power source, 2 ... Charger, 3 ... Circuit breaker,
4 ... Transformer, 5, 9, 10, 11 ... Rectifier, 6, 7, 8
... Switching circuit, 12 ... Charge detector, 13, 14, 15
… Batteries.

Claims (1)

[Claims] 1. A method of connecting a plurality of storage batteries to a charger and switching a current in two stages to charge the battery, wherein a rectifier having a large current charging current capacity among the two-stage charging currents and a number of charging terminals are provided. The charging of the storage battery from the rectifier having the small current charging current capacity of, and the charging of the storage battery from the rectifier having the large current charging current capacity is performed by time-division charging before each of the storage batteries completes charging. Characteristic multiple battery parallel charging device.