CN2617042Y - rechargeable battery unit - Google Patents

Abstract

A rechargeable battery device comprises a hollow shell, a lithium battery and a voltage limiting circuit, wherein the shell is provided with a first end, a second end opposite to the first end, a first conductive part arranged on the first end and a second conductive part arranged on one of the first end and the second end, the lithium battery is arranged in the shell, the positive pole and the negative pole of the lithium battery are respectively in conductive connection with the first conductive part and the second conductive part, the voltage limiting circuit is arranged in the shell and is in conductive connection with the positive pole and the negative pole of the lithium battery, and the voltage limiting circuit is used for reducing the output voltage of the lithium battery to a preset voltage range, so that the lithium battery can be used for supplying power without the problem of overlarge output voltage.

Description

rechargeable battery unit

【Technical field】

The utility model relates to a rechargeable battery device, in particular to a rechargeable battery device which mainly uses a lithium battery and can limit its output voltage within a certain range.

【Background technique】

Generally, dry batteries are often used to supply DC power in small electronic devices. In terms of the classification of dry batteries, they can be divided into primary batteries that can only be used once, and secondary batteries that can be recharged and used (also known as rechargeable batteries).

Typical primary batteries are carbon-zinc batteries and alkaline batteries. However, in consideration of environmental protection and economy, rechargeable batteries that can be recycled have gradually become the mainstream of future batteries. In terms of their materials, they can be roughly divided into nickel-cadmium batteries. , Ni-MH batteries, and lithium batteries are three categories, the following three types are explained separately:

The output voltage of nickel-cadmium batteries is about 1.2 volts, and has the advantages of low cost and fast charging. However, the cadmium metal in nickel-cadmium batteries is easy to cause environmental pollution, and nickel-cadmium batteries have serious battery memory effects, so Not suitable for long-term use.

Ni-MH batteries, whose output voltage is about 1.2 volts, replace the cadmium metal used in the original nickel-cadmium batteries with hydrogen storage alloys, and can effectively improve the memory effect of nickel-cadmium batteries, but the disadvantage is that they are easily affected by temperature and have Slight memory effect.

Lithium batteries, whose output voltage is about 3.6 volts, have the advantages of high energy density, long cycle life, and no memory effect, so they are currently widely used in consumer electronics such as portable phones, notebook computers, and personal digital assistants. .

In fact, although the above-mentioned nickel-cadmium battery and nickel-hydrogen battery have the advantage of being reusable, however, because their output voltage is only about 1.2 volts, which is lower than the output voltage of 1.5 volts of the primary battery, they often cannot provide power to the load. Continuous drive force, even if the output voltage is too low to activate the electronics.

On the other hand, although the lithium battery has a high output voltage, its output voltage as high as 3.6 volts is not very suitable for electronic devices that generally do not have a power management system, such as radios, small game consoles, etc., and may Cause the load to be burned and damaged due to excessive current.

【Contents of Utility Models】

Therefore, the purpose of the present utility model is to provide a rechargeable battery device which uses a lithium battery as a power source and can control the output voltage.

Therefore, the rechargeable battery device of the present invention includes a hollow casing, a lithium battery, and a voltage limiting circuit.

The casing has a first end, a second end opposite to the first end, a first conductive portion disposed on the first end, and a first end disposed on one of the first end and the second end. on the second conductive part. The lithium battery is arranged in the casing, and the positive and negative poles of the lithium battery are connected to the first conductive part and the second conductive part respectively. The voltage limiting circuit is set in the shell and connected with the positive and negative poles of the lithium battery. The voltage limiting circuit is used to reduce the output voltage of the lithium battery to a predetermined voltage range, so it can be used for general Electronic devices will not be damaged or burned due to excessive output voltage and excessive current.

【Description of drawings】

The rechargeable battery device of the present utility model is described in detail below through the preferred embodiment and the accompanying drawings, in the accompanying drawings:

Fig. 1 is a perspective view illustrating a preferred embodiment of the rechargeable battery device of the present invention.

FIG. 2 is a schematic circuit diagram illustrating the discharge of the preferred embodiment connected to a load.

FIG. 3 is a schematic circuit diagram illustrating a protection circuit of the preferred embodiment for overcharging protection.

FIG. 4 is a schematic circuit diagram illustrating that the protection circuit performs over-discharge protection.

FIG. 5 is a schematic circuit diagram illustrating that the protection circuit performs short-circuit current protection.

FIG. 6 is a schematic circuit diagram illustrating the charging of the preferred embodiment connected to a charger.

【Detailed ways】

Referring to FIG. 1 and FIG. 2 , a preferred embodiment of the rechargeable battery device 100 of the present invention includes a hollow casing 1 , a lithium battery 2 , and a voltage limiting circuit 3 .

The housing 1 has a first end 11, a second end 12 opposite to the first end 11, and a first conductive portion 111 and a second conductive portion respectively disposed on both sides of the first end 11. 112. It must be noted that although in this embodiment, both the first conductive part 111 and the second conductive part 112 are arranged on the first end 11, in fact, the first conductive part 111 can also be arranged on the first end 11 However, disposing the second conductive portion 112 on the second end 12 does not affect the action of the present invention. In addition, the size of the housing 1 is about two AA batteries (AA batteries) side by side, which is equal to the size of a CRV-3 battery, so it can be used in digital cameras, or other types that can accommodate two AA batteries. in the electronic unit of the battery holder with the batteries side by side.

The lithium battery 2 is disposed in the housing 1 . The lithium battery 2 has two battery bodies 21 connected in parallel and a protection circuit 22 connected in parallel with the battery bodies 21 . The positive and negative poles of each battery body 21 are respectively connected to the first and second conductive parts 111 and 112, so they can be connected to a load 200 through the first and second conductive parts 111 and 112 to achieve The purpose of using the battery body 21 to supply power is to use a charger (not shown) to charge the battery body 21 through the first and second conductive parts 111 , 112 .

Those who are familiar with this technology know that once the battery body 21 of the lithium battery 2 is over-charged, the electrolyte in the battery body 21 will be decomposed, causing the temperature to rise and generate gas, which may cause the danger of spontaneous combustion or explosion . If the battery body 21 is over-discharged, the electrolyte solution in the battery body 21 will decompose and cause battery characteristics to deteriorate, resulting in a reduction in the number of times the battery body 21 can be charged. On the other hand, if an excess current or a short-circuit current occurs due to unknown reasons (eg, the positive and negative terminals are accidentally touched by a metal object during discharge), the battery body 21 may also be permanently damaged.

Therefore, the protection circuit 22 is used to prevent the battery body 21 from overcharging and overdischarging, and to protect the battery body 21 from short circuit current. The protection circuit 22 mainly has a protection IC 221, two metal-oxide-semiconductor field-effect transistors (MOSFET) Q1, Q2, and two diodes D1, D2 respectively connected between the drain-source (drain-source) of the transistors Q1, Q2 . The protection IC 221, for example, can adopt the chip of R5426 manufactured by Ricoh Company, but it is not limited thereto. It is connected with the battery body 21, so it can monitor the voltage state of the battery body 21. In the case of the situation, the on and off of the transistors Q1 and Q2 are controlled to further protect the battery body 21. The protection mechanism will be described below, and for the convenience of description, the transistors Q1 and Q2 in the drawing are in the form of switches to express.

(1) Overcharge protection: As shown in Figure 3, when an external charger 300 charges the lithium battery 2, the current direction is as shown by the arrow in the figure, at this time the voltage of the battery body 21 will gradually rise, and the protection IC 221 When it is detected that the voltage of the battery body 21 reaches 4.25 volts (assuming that the overcharge voltage of the battery body 21 is 4.25V) through two points a and b, the protection IC 221 controls the transistor Q1 to turn on (turn on), and the transistor Q2 to turn off (cut off), so that the current cannot reversely flow through the diode D2, so the charger 300 can be stopped to continue charging the battery body 21, so as to achieve the purpose of overcharging protection.

(2) Over-discharge protection: As shown in Figure 4, assuming that the lithium battery 2 is connected to the load 200, when the protection IC 221 detects that the voltage of the battery body 21 is lower than 2.3 volts (assuming that the minimum discharge voltage of the battery body 21 is 2.3 volts V), the transistor Q2 is controlled to be turned on, and the transistor Q1 is turned off, so that the current cannot reversely flow through the diode D1, so that the battery body 21 can stop supplying power to achieve the purpose of over-discharge protection.

(3) Short-circuit current protection: As shown in Figure 5, when the discharge current is too large or a short-circuit occurs, the over-current detection of the protection IC 221 is to use points b and c to detect both sides of the transistors Q1 and Q2 (in other words, transistors Q1 and Q2 are regarded as resistors), if the voltage drop is greater than a predetermined current detection voltage (for example, 0.2V), the transistor Q1 will be cut off, so that the battery body 21 will stop supplying power to achieve short-circuit current protection. Purpose.

Returning to FIG. 2 , the voltage limiting circuit 3 is connected to the battery body 21 and has a differential amplifier 31 , a transistor Q3 , and a voltage divider 32 . The voltage divider 32 is composed of resistors R1 and R2, and inputs the sampled voltage V1 to the positive input terminal of the differential amplifier 31. On the other hand, the negative input terminal of the differential amplifier 31 receives a reference voltage (Vref ), and the output terminal of the differential amplifier 31 is connected to the gate of the transistor Q3. In this embodiment, the reference voltage is selected to be 1.23 volts. Therefore, when the sampling voltage V1 is greater than the reference voltage Vref, the transistor Q3 is turned on, otherwise, the transistor Q3 is turned off so that the current cannot flow.

Therefore, when the battery body 21 of the lithium battery 2 is discharged, the differential amplifier 31 turns on the transistor Q3. In this embodiment, the transistor Q3 is operated in the tripolar region, that is, the transistor Q3 is used as a voltage-controlled resistor, so that the horizontal The voltage drop across the drain-source of the transistor Q3 is about 0.5 volts. In other words, the battery body 21 whose original output voltage is about 3.6 volts has been reduced to about 3 volts (3.6-0.5=3.1), This output voltage has been accepted by general electronic devices. Of course, if the output voltage of the battery body 21 is too low so that V1 is lower than Vref, the differential amplifier 31 can turn off the transistor Q3 and stop discharging, and also has the effect of over-discharge protection.

On the other hand, in order not to be affected by the voltage limiting circuit 3 during charging, the utility model further includes a diode D3 across the voltage limiting circuit 3. In this embodiment, in order to utilize a lower opening voltage and consider To low power consumption and other issues, so Schottky diode (Schot tky diode) is used. As shown in Figure 6, when charging with the charger 300, since the diode D3 is off, the current will bypass the voltage limiting circuit 3 through the diode D3, so that the charging is not limited by the voltage limiting circuit 3 Influence. Of course, if abnormal conditions such as over-discharging and over-charging occur, the protection IC 221 will automatically activate and turn off the transistors Q1 and Q2 to achieve its protection mechanism. This point has been described in detail above.

It should be noted that the above-mentioned voltage limiting circuit 3 and protection circuit 22 can be fabricated on a printed circuit board (not shown in the figure) first, and then installed in the casing 1 in a modular manner and connected to the battery body 21. connection, or integrate the voltage limiting circuit 3 and the protection circuit 22 in the form of a single chip, and then connect the single chip with the battery body 21, which is just a simple change.

Therefore, by the above-mentioned configuration, the output of the lithium battery 2 can be used by general electronic devices. Even better, since the casing 1 is designed to be the size of two AA batteries connected in parallel, it can be used in a battery holder An electronic device designed with a pair of AA batteries, such as a digital camera. Furthermore, since two parallel lithium battery bodies 21 are used for power supply, higher energy density and longer battery life can be provided.

To sum up the above, the rechargeable battery device 100 of the present invention uses a lithium battery 2 with no memory effect and high cycle life as the power supply source, and uses a voltage limiting circuit 3 to reduce the output voltage of the lithium battery 2, so that the internal unused Equipped with an electronic device such as a voltage reducer, a DC to DC converter (DC to DC converter), etc., it can indeed achieve the purpose of the present utility model.

Claims (5)

1, a kind of charging cell device is characterized in that including:

One hollow housing has one first end, second end, opposite with this first end is arranged at first conductive part on this first end, and one is arranged at this first end and this second end second conductive part on one of them;

One lithium battery is arranged in this housing, the positive and negative polarities of this lithium battery and be to connect mutually with this first conductive part, this second conductive part respectively; And

One pressure limiting circuit is arranged in this housing and with the positive and negative polarities of this lithium battery and connects mutually, and this pressure limiting circuit is to be reduced in the predetermined voltage range in order to the output voltage with this lithium battery.

2, charging cell device as claimed in claim 1; it is characterized in that: this lithium battery has a battery body; an and protective circuit that connects mutually with this battery body; this protective circuit is in order to preventing that this battery body from overcharging, overdischarge, and this battery body is carried out the short circuit current protection.

3, charging cell device as claimed in claim 1 is characterized in that: the size of this housing is to approximate two No. 3 batteries size side by side.

4, charging cell device as claimed in claim 1, it is characterized in that: this pressure limiting circuit has a differential amplifier, a transistor, an and voltage divider, two inputs of this differential amplifier are a voltage and reference voltages of accepting this voltage divider respectively, and the output of this differential amplifier is to be connected on this transistorized gate.

5, charging cell device as claimed in claim 1, it is characterized in that: this charging cell device more comprises a diode of crossing from this pressure limiting circuit bypass, this diode provides a power source path, can not be subjected to the influence of pressure limiting circuit when making this lithium cell charging.

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