CN101145606A

CN101145606A - Energy balance lead-acid storage battery

Info

Publication number: CN101145606A
Application number: CNA2007100705197A
Authority: CN
Inventors: 林子进
Original assignee: Taizhou Zhengfangwei Electronic Co ltd
Current assignee: Taizhou Zhengfangwei Electronic Co ltd
Priority date: 2007-08-18
Filing date: 2007-08-18
Publication date: 2008-03-19

Abstract

An energy balance accumulator is composed of two or more than two single accumulators connected in series, a balance rod between the polar plates of each accumulator and composed of positive pole of accumulator and negative pole of balance rod, and a shunt regulator with resistance value of 0.01-2 omega, reference voltage value of 2.20-2.40V, reference voltage temp variation value less than 120 ppm/deg.C and forward leakage current less than 50uA. The invention has simple structure and low manufacturing cost, can evenly distribute the energy among the single storage batteries and effectively solves the problem of backward single storage batteries.

Description

Energy balance lead-acid storage battery

Technical Field

The invention belongs to the technical field of lead-acid storage batteries, and particularly relates to a lead-acid storage battery capable of avoiding overcharge and undercharge.

Background

The lead-acid storage battery has stable discharge working voltage, can discharge by small current and large current, has wide working temperature range, can work at the temperature of between 40 ℃ below zero and 65 ℃, has mature technology, low cost and good output characteristic along with load, and becomes an important product with wider use.

However, the existing lead-acid storage battery has the obvious defects of large mass, low mass specific energy and short cycle service life. The service life of the lead-acid storage battery depends on the charging current and the charging time, and the duration of the charging time is in direct proportion to the discharge depth of the storage battery, namely, the service life of the lead-acid storage battery is shortened as the charging current is larger and the discharge depth is deeper. The storage batteries are easy to age too early and have short service life due to the overcharge and the undercharge of the storage batteries and the energy imbalance among the storage batteries. The temperature can rise rapidly due to monomer unbalance, thermal runaway can be caused, the battery shell bulges and deforms, electrolyte sulfuric acid overflows from the sealing position of the battery, the battery is dehydrated due to overcharge of the battery, and capacity reduction is inevitably caused due to insufficient supply of raw materials required by dehydration in chemical reaction inside the battery.

In order to solve the problem of monomer unbalance, domestic and foreign research institutions and battery enterprises are dedicated to searching and researching corresponding technologies. Chinese utility model patent CN2154538Y "combined rechargeable alkaline zinc-manganese dioxide cell", but the shunt control circuit of an automatic break-make connects in parallel between every rechargeable alkaline zinc-manganese dioxide cell, this shunt control circuit comprises two diodes and a resistance, the voltage limiting is made to the diode, the resistance is made the current-limiting, this technical scheme only is applicable to alkaline zinc-manganese dioxide cell and shunts with the silicon diode, the operating voltage scope is bigger, operating voltage risees along with the increase of electric current, the voltage drift that switches on along with the rise of temperature is also bigger, forward leakage current is bigger (milliampere level), can only install in charger circuit, when combining with the battery, it will obviously shorten battery storage life to leak and leak.

Lonnie g.johnson, smyma, 1997, usa; the invention relates to a rechargeable battery power supply overcharge protection circuit (US 5982144) invented by Yong Su, atlanta, both of Ga, which adopts shunt integration as a core for constant-value voltage-stabilizing charge protection, adopts an integrated voltage-stabilizing circuit for timing charge, and when the storage batteries are charged at the same voltage, the storage batteries of all the single batteries need different full charge time, but when the storage batteries are charged at the same time and the same voltage, certain errors exist among the performance of all the single batteries in the storage batteries, and then the overcharging and the undercharging with errors can be generated. In addition, the existing detection circuit judges whether the storage battery is fully charged or not according to the magnitude of the charging current, and the saturation of the battery cannot be detected by adopting constant-value voltage stabilization.

The invention patent CN1592997A (publication date 3/9/2005) of China, which is applied by the American zinc matrix power company, "storage battery charging system" is an improvement on the basis of US5982144, but the core principle is the same as the above US5982144, and the problems of over-charging and under-charging with error are not overcome by using shunt integration as the core for constant-value voltage-stabilizing charging protection.

The inventor proposes CN2896539 "energy balancing battery" and CN1767246 "energy balancing battery balancing bar", CN1889298 'energy balance accumulator balance bar', in order to overcome the over-charge and under-charge of single accumulator to ensure the energy balance among the single accumulator, the two ends of each single storage battery are connected in parallel with a balance bar which is a voltage-limiting shunt circuit, so that the performance of the single storage battery is improved to a certain extent, but the defect of insufficient capacity improvement of the lead-acid storage battery still exists.

In the current lead-acid storage battery industry, the valve control type sealed lead-acid storage battery becomes a mainstream product, and because the structure of the valve control type sealed lead-acid storage battery is totally sealed, only two electrodes are exposed, and the error between the monomer and the monomer in the interior of one storage battery is quite small, which is about 0.2% -2%. The prior art of the above-mentioned patent is still unsolved.

In view of the above, a solution is needed to effectively protect the lead-acid storage battery from undercharging and overcharging, so that the overall capacity of the lead-acid storage battery can be reflected, and the service cycle life of the lead-acid storage battery can be prolonged.

Disclosure of Invention

The invention aims to provide an energy balance lead-acid storage battery which can fully improve the capacity of the lead-acid storage battery and prolong the service life.

The technical scheme adopted by the invention for solving the technical problems is as follows:

an energy balance storage battery is composed of two or more single storage batteries connected in series, a balance bar is arranged between polar plates of each single storage battery, the positive electrode of each single storage battery is connected with the positive electrode of the balance bar, the negative electrode of each single storage battery is connected with the negative electrode of the balance bar, the forward voltage drop of the balance bar is larger than the actual maximum voltage of each single storage battery and smaller than the charging voltage of each single storage battery, and the energy balance storage battery is characterized in that the balance bar is composed of a resistor R and a shunt voltage stabilizer IC connected in series, the resistance value of the resistor is 0.01-2 omega, the reference voltage value of the shunt voltage stabilizer is 2.20-2.40V, the reference voltage temperature variation value is smaller than 120 ppm/DEG C, and the forward leakage current is smaller than 50uA.

The invention adopts a shunt regulator IC (integrated circuit) with high voltage-stabilizing precision, and can effectively solve the problem of small error between the internal monomers of the storage battery.

When the single storage battery is unbalanced, the voltages at two ends of the single storage battery change, and the balanced current changes suddenly due to the high voltage stabilization precision of the shunt voltage stabilizer IC (integrated circuit) and the resistance value of the resistor between 0.01 omega and 2 omega; according to the principle of physical capacity, the capacity Q = I.t of the storage battery, and the balance between the single cells in the storage battery can be effectively controlled by changing the current. The highest single voltage of the lead-acid storage battery is 2.2V, and the highest floating charge voltage is 2.4V during charging, so that the IC reference voltage stabilization value of the shunt voltage stabilizer is 2.20V-2.4V; meanwhile, the error between the internal single body of the storage battery and the single body is quite small, the reference voltage temperature variation value of the shunt voltage stabilizer is limited to be less than 120 ppm/DEG C, the balance bar is connected with the single storage battery in parallel for a long time to play a protection role and cannot form a load, and the forward leakage current of the shunt voltage stabilizer is limited to be less than 50uA.

The resistance value of the resistor can be adjusted according to the capacity of the storage battery, the larger the capacity of the storage battery is, the lower resistance value of the resistor is selected, and the working current of the balance bar is determined according to the capacity and the application of the lead-acid storage battery.

The working principle of the invention is as follows:

assuming that one of the single storage batteries lags 5% and the normal working current of the balancing bar is 50mA, when the 1A constant current is used for charging, the current passing through the rest single storage batteries is 0.95A, and the current passing through the balancing bar connected in parallel with the two ends of the balancing bar is 0.05A; the current passing through the lagging battery cell is 1A, and the current passing through the two ends of the lagging battery cell in parallel is less than 50 muA. In the charging process, the current passing through the single storage batteries is constantly changed, and the current magnitude of the balance rods connected with the two ends of the single storage batteries in parallel is changed accordingly, so that the ionization uniformity of each single storage battery is ensured, and the difference of each single storage battery is promoted to tend to be balanced.

The energy balance storage battery has the performance of uniform energy distribution, can effectively balance each monomer to work normally after the monomers fall, and has little influence on the whole by the voltage deviation, the discharge depth and the capacity tolerance among the monomers of the storage battery.

The energy balance storage battery of the invention reduces the probability of overcharge to the lowest, and avoids overcharge of partial monomers. When the storage battery is just delivered from the factory, the monomer lag is very small, after the storage battery is discharged every time, the storage battery is repaired and restored as before by the method, and the charging voltage distribution is relatively uniform; the charging voltage is a fixed value, for example, a 12V lead-acid storage battery is composed of 6 monomers, the float charging voltage is 14.4V, each unit cell voltage is 2.4V, the solution in the storage battery contains lead sulfate, sulfuric acid and water, after the lead sulfate in the solution is completely ionized, the leakage current of each monomer is a fixed value, the voltage and the current of a balance rod are fixed values, most of chargers in the prior art control whether the storage battery is fully charged by monitoring the current, the energy balance storage battery of the invention has no influence on a detection circuit, so that the detection circuit can be used for avoiding overcharge or undercharge by detecting the saturation of the battery, and the service life of the storage battery can be prolonged.

Compared with the storage battery in the prior art, the storage battery has the beneficial effects that the production cost is low, the price of one balance bar of the storage battery such as a 20Ah lead-acid storage battery is about 0.7 yuan RMB, and the storage battery adopting the circuit arrangement of overcharge prevention and the like in the prior art is 2 times higher.

Drawings

FIG. 1 is a schematic diagram of an energy balance battery according to the present invention;

FIG. 2 is a schematic diagram of the structure of the balancing bar of FIG. 1;

FIG. 3 is a schematic view of an energy balance battery mounting configuration of the present invention wherein the balancing bar is disposed within the battery;

fig. 4 is a schematic view of another mounting structure of the energy balance storage battery, wherein the balance bar is arranged outside the storage battery.

Detailed Description

The following detailed description of the invention, as well as the following drawings, will provide a clear understanding of the invention.

The energy balance bar shown in fig. 1 is composed of a resistor R and a shunt regulator IC, wherein the resistance value of R is 0.01 Ω -2 Ω, and the reference voltage value of the shunt regulator IC is in the range of 2.20V-2.40V.

The energy balance storage battery shown in fig. 2 is composed of three single storage batteries a, B and C which are connected in series, a balance bar is arranged between polar plates 4 of each single storage battery, the anodes of the single storage batteries a, B and C are respectively connected with the anodes of the

balance bars

1, 2 and 3, and the cathodes of the single storage batteries a, B and C are respectively connected with the cathodes of the

balance bars

1, 2 and 3.

Three single storage batteries A, B and C, a polar plate 4, a separator 5, an electric tank 6 and electrolyte 7 are arranged in a shell and are arranged in an upper cover 8,

balance bars

1, 2 and 3 are arranged in the storage batteries and are separated from the electrolyte 7 by the separator 5 in figure 3, and the

balance bars

1, 2 and 3 are arranged outside the storage batteries in figure 4.

The

balance bars

1, 2 and 3 are all formed by connecting a resistor R and an IC shunt voltage stabilizer 8 in series, the resistance of the resistor R is less than 2 omega, the resistor R can be a metal film resistor, and the resistance can be: 100mA-1 Ω,133 mA-0.75 Ω,200mA-0.5 Ω,300mA-0.33 Ω, and so on. At the moment of switching on the power supply, the peak-peak value of the positive or negative half cycle of the power supply can generate a large instant current, and the current-limiting resistor R can ensure the safety of the circuit.

The voltage stabilizing value of the shunt voltage stabilizer 8 is 2.20V-2.40V, the temperature variation value of the reference voltage is less than 120 ppm/DEG C, and the forward leakage current is less than 50uA. The working current is determined according to the capacity and the application of the lead-acid storage battery.

The integrated circuit of the shunt regulator 8 only needs to meet the requirements that the voltage stabilizing value is between 2.20V and 2.40V, the temperature variation value of the reference voltage is less than 120 ppm/DEG C, and the forward leakage current is less than 50uA. Since those skilled in the art of circuit design can design various shunt voltage regulator circuits according to the above parameters, they are not illustrated here.

The working process of the accumulator is reanalyzed from the present embodiment

The storage battery pack comprises a single storage battery A, a single storage battery B and a single storage battery C, the resistor and the shunt voltage stabilizer 1 are connected in parallel with the single storage battery A, the resistor and the shunt voltage stabilizer 2 are connected in parallel with the single storage battery B, and the resistor 3 and the shunt voltage stabilizer 3 are connected in parallel with the single storage battery C. Assuming that lead sulfate is generated through the first discharge reaction, the lead ions A, B and C in each lead sulfate monomer are 1000, 980 and 1000, and the concentration of sulfuric acid is the same, the monomer lag is 2%.

The first charging is carried out, the lead sulfate A and the lead sulfate C have higher concentration and smaller internal resistance, and the lead sulfate B has lower concentration and larger internal resistance; when energized, the voltage drops across them are different for the same current, i.e. U _A ＝U _c <U _B When the current of the balance bar 2 connected in parallel with the single storage battery B is suddenly changed, the charging voltage U of the lead-acid storage battery is more than or equal to 2.4V and the charging current I is more than or equal to 15% ₂ Per, initial charging voltage U of each cellMore than or equal to 2.3V, the voltage is in direct proportion to the charging current, and at the moment, U is _B >U _A ＝U _C Since the

balance bars

1, 2 and 3 are connected in parallel on the ABC, U is connected in parallel _A ＝U ₁ 、U _B ＝U ₂ 、U _C ＝U ₃ I.e. U ₂ >U ₁ ＝U ₃ 。

When the current limiting resistor R of the balance bar is assumed to be 0.5 omega, the reference voltage stabilization value of the shunt voltage stabilizer is 2.30V, and the single charging voltage is 2.40V; when U is turned ₂ -U ₁ ＝0.01V，

I_{2} - I_{1} = \frac{0.01 V}{0.5 Ω} = 20 mA

Current I of _{General (1)} ＝I _A +I ₁ ＝I _B +I ₂ ＝I _C +I ₃ Then, I _A -I _B =20mA; if U is present ₂ -U ₁ When =0.02V, I ₂ -I ₁ =0.02V/0.5 Ω =40mA, then I _A -I _B ＝40mA。

As shown in fig. 1, the current of the balance bar changes depending on the voltage at the two ends of the balance bar, and the voltage at the point a is stable, so the voltage at the two ends of the balance bar changes, and the current of the balance bar changes accordingly; from the energy formula, Q = It is again considered, that is, the size of the battery capacity depends on how much energy Q is stored, and the size of energy Q depends on the product of the size of current I and the length of time t, so that the battery cell lag must be controlled from the size of current.

Experiments prove that the reference voltage stabilizing value of the shunt voltage stabilizer IC adopted by the invention is in the range of 2.20V-2.40V, the temperature variation value of the reference voltage is less than 120 ppm/DEG C, the working stability of the integrated circuit of the shunt voltage stabilizer is high at different temperatures, and when the forward leakage current is less than 50uA, the balance bar hardly becomes a load when the storage battery does not work. Therefore, the balance bar can repair the monomer behind as before, and the balance bar can completely ionize the lead sulfate in each monomer in the same time and perform long-term tracking control.

Capacity fade and life test:

testing the battery: 9 6-DZM-10 valve-controlled lead-acid storage batteries produced in the same batch are divided into two groups, wherein the balance rod is not added in the first group, and 9 batteries are added in the first group; the second group is 9 energy balance storage batteries of the invention.

An experimental instrument: 3 digital desk type universal meters (MS 8050), 1 digital thermometer and temperature data collector (1502A type thermal Resistor (RTD)) 1, 1 LQY-1 type vibration cylinder barometer, 1 handle of 300mm digital vernier caliper, 1 intelligent lead-acid battery charging and discharging controller and 1 XRL-battery capacity tester; the resolution and precision of all instruments meet the requirements of the test method of the standard GB/T19639.1-2005 technical conditions of small valve-controlled sealed lead-acid batteries.

The experimental method comprises the following steps: GB/T19639.1-2005 technical Condition of Small valve-regulated sealed lead-acid Battery

And (4) carrying out a cycle test on 18 lead-acid storage batteries, and carrying out a capacity test firstly.

The test results were as follows: the first group 9 has the capacity of 10Ah, and the second group 9 has the capacity of 10.5Ah; carrying out a cycle test according to a GB/T19639.1-2005 life test method;

after a four month and half time test; the first group has 6 service lives of 400 times, 2 times of 480 times and 1 time of 600 times;

in the second group, 9, no capacity fade was observed after 600 cycles.

The comparative experiment proves that the capacity of the invention is 5% higher than that of the invention without the use, and the service life is improved by 5 times.

The service life of the existing storage battery is short because the storage battery is charged if the storage battery is used singlyBackward U _B -U _A、C When =0.08V, the float voltage is 14.4v _A、C ＝2.36V，U _B =2.44V, if it is standard that each cell voltage is 2.4V, that U _A、C If 2.36V is exceeded, U is formed _B Over-charging occurs when 2.44V, and if AB is not wanted, the cell battery B is over-charged more and therefore the battery will end up in a short life.

In the charging process, the energy balance storage battery ensures the ionization uniformity of each single storage battery through the balance of the shunt voltage stabilizer and the low-resistance resistor, so that the difference of each single storage battery tends to be balanced.

The charging process of the storage battery is divided into three stages, wherein the first stage is constant current charging, the second stage is voltage stabilization charging, and the third stage is a state of stopping charging or charging dormancy; during the first stage of constant current charging, the balance bars start to work, the working voltage values of the balance bars in the same storage battery are basically the same, the error is within 0.01V, when the single bodies in the storage battery are unbalanced, the charging voltage values of the single bodies are different, namely the current passing through the balance bars are also different, and therefore the backward single bodies are balanced; the second stage and the first stage, the balancing rod works until the batteries are balanced; and entering a third stage, if the charger is charged finally, the balancing bar stops working because the forward voltage drop of the balancing bar is greater than the actual highest voltage of the single storage battery and less than the charging voltage of the single storage battery, and if the charger enters a dormant state, the balancing bar continues working.

Claims

1. An energy balance accumulator is composed of two or more than two single accumulators connected in series, a balance bar is installed between polar plates of mother single accumulator, and includes the connection of positive pole of single accumulator with positive pole of balance bar, the connection of negative pole of single accumulator with negative pole of balance bar, the positive voltage drop of said balance bar is greater than the actual maximum voltage of single accumulator and less than the charging voltage of single accumulator, it is characterized by that said balance bar is composed of a resistor R and shunt regulator IC, the resistance value of said resistor is 0.01 omega-2 omega, the reference voltage value of said shunt regulator is 2.20V-2.40V, the temperature variation value of reference voltage is less than 120 ppm/deg.C, and the positive leakage current is less than 50uA.