digital batteries

In practice, due to the difference between two lithium batteries monomers, after a period of loading and unloading of the battery and found the only upper and lower voltage appears uneven phenomenon seriously affect system performance. In response to this situation raises the equilibrium and under the concept of equilibrium, then the lithium Laptop battery, the next in-depth study of a balanced circuit. Experimental results show that lithium batteries several correctness of circuit design balanced system design of high performance hybrid has laid a solid foundation.

Devices for energy storage for dynamic current of the battery are: the lead-acid batteries, nickel-hydride batteries, metal and lithium-ion batteries.

Span of lead acid batteries contain toxic substances like lead, and high energy density is low, charge and discharge and short life, the refractory waste and other shortcomings, has been largely eliminated by future systems energy storage [1].

Ni-MH batteries are alkaline batteries, due to tension monomer is relatively low, and there is “memory effect” on a regular basis the large-scale dumping is necessary, which greatly increased the tasks of system power management . Secondly, its also self-discharge rate (10% ~ 15%) of defects [2-3].

In comparison with other batteries, lithium-ion IBM ThinkPad T40 battery with high power density (800W/Kg), single high-voltage (average voltage of 3.6 V), does not pollute the environment, self-rate discharge is low (about 3% ~ 5%), there is no “memory effect” and other characteristics, is an ideal battery power [4], it has been widely used in mobile power , hybrid cars, the switchgear and low voltage devices in standby power, such as space flight, the device energy storage.

An internal force of the lithium-circuit fault protection

Monomer average voltage of lithium battery is only 3.6 V, the discharge current also certain requirements. To improve the current system and level of tension, in some occasions, generally use parallel dynamic series after the formation of high-current, high voltage Li-ion battery as the energy systems. As the voltage is very sensitive to lithium batteries, batteries are generally increased when using a certain protection circuit. View the most dynamic of the internal circuitry of lithium battery protection was found, its protection circuit is fairly simple, usually only over / under voltage / over current / short circuit protection. In normal use, this hp F4486B battery can be normal in a short time of loading and unloading. However, the inclusion of the protection circuit with lithium batteries used in systems for hybrid electric vehicles are going through a phase of high current discharge and charge, we found the maximum voltage between monomers and lower voltages serious inconsistency: Yes monomer other batteries in charging the battery voltage is always under normal conditions, because its threshold voltage has reached the maximum protection of recharge channels are closed, resulting in the total pressure on the entire energy system can not pre-determined requirements, another set of monomer battery voltage is still within the normal discharge conditions, because of its voltage reaches the lower threshold voltage is closed to protect discharge channel, causing the entire energy system can not be fully discharged. These two phenomena have seriously affected the performance of energy systems for monitoring the equalization of the toshiba PA3383U-1BRS battery is to solve the above-mentioned phenomenon of the most effective approach.

2 Improved Lithium Battery Protection Circuit Principle

A balanced circuit is the first man to reach the hardware circuit, which may limit the battery voltage of the monomer or monomer between the coherence between the minimum voltage to effectively protect the battery charge voltage and lower the ceiling voltage discharge , from a fundamental to reduce the impact of the battery on the system to improve battery performance and extended to battery life. It includes the balance and balance of both types of circuit to its name suggests, they were the maximum protection of the battery voltage and the voltage limit of the battery.

In this paper, two sets of vehicle design hybrid electric power system: Series 3 Li-ion battery system protection (maximum voltage of 12.75V, the average discharge voltage of 10.8 V) and channel 10 system lithium apple M8403 battery protection (maximum voltage of 42.5V, the average discharge voltage 36V), discharge current, 10A and 40A respectively. System principle illustrated in Figure 1, which is in its protective circuit basis (over / under voltage / temperature / over current / short circuit protection) based joins the upper and lower balance circuit.

2.1 EQ TL431

TL431 is a three-terminal shunt tube regulator, its basic features can be found in reference [5] This article, based on the characteristics of their designs on the balance of the circuit shown in Figure 2. Adjust R1, R2, R3 resistance when the voltage exceeds a set value when they opened TL431, through the resistor R * Power consumption of energy to reduce battery voltage to reach a fixed point (equilibrium point). With the internal electric vehicles and electric vehicles equipped with a balanced circuit experimental results when the balance to be 4.20V, the resistance values are: R1 = 68kΩ, R2 = 100kΩ, R3 = 4.3kΩ.

The balance of the next circuit based on TL431 as shown in Figure 3. When the switch is off, because of optocoupler 817 is not opened before the class to optocoupler circuit also unable to work after school, the work of the BATCL50L battery in a state of normal discharge; When closed, the Post optocoupler optocoupler stage with the opening of the first class one after another opened, the circuit through the resistor R18 to reduce energy consumption and protect the chips sent until the voltage battery is low to protect the chip to force the battery voltage is stable at its low voltage limit Vmin, to achieve the objective and balanced.

From this principle of a balanced circuit can be seen that the current balance of the circuit can not exceed the upper limit of protection TL431 current (70mA or so). Capacity constraints due to a balanced, high-current charge and discharge can be applied between the circuit. To increase the balance of the circuit without compromising the ability of TL431, the TL431 can be used in parallel.

2.2 Parallel equalizer TL431

TL431 shunt and balanced the circuit shown in Figure 4. The principle is similar to Figure 3, only through parallel TL431 for the balanced expansion of current targets. Found in the actual production, as TL431 has a small difference between doing two average balance of power is not entirely consistent. To reduce the occurrence of these phenomena, the general screening methods to improve the TL431 for these circuits, which probably increased the workload of production.

2.3 Improving the equalizer TL431

To improve the balance of the capacity of the circuit, while reducing the workload of the TL431 output filter, this article using the 8550 design of an improved balance of the circuit of power transistor as shown in Figure 5. Once the extra power when TL431 will open, 8550 launch of a PN junction due to handle pressure and opening resistors consumes IBM ThinkPad T41 battery power until the battery voltage on the equilibrium point. Once balanced, the figure would be light-emitting light-emitting diode has played the role of operational instructions. By adjusting the set R1, R2, R3 resistance, they can set the balance point of the upper spring. Figure R1, R2, R3 resistance is relatively large, after the close of the TL431 little effect on the equilibrium point can be ignored. And the balanced circuit is also shown in Figure 5, only a change of R1, R2, R3 corresponding resistance.

3 Experimental results

The compositions of these functions with a string of 10 Office of Protection of lithium batteries a 400W DC motor driven experiments and found that all protective plates in a lithium battery when the total pressure of about 42.5V charging off tube protection against surges on the ground, pressure or almost total 29.2V for the discharge out of the market when the protection of the tube voltage, protecting the plate with a battery pack lithium in the testing stage for overcurrent detected: discharge current of 39A or more, the protective panels were made over-current protection, temperature of 109 ° C when the switch in the off-discharge circuit, the effective protection of the market of the discharge tube. The above data indicate that the circuit is essentially achieved the over / under voltage / over current / over-temperature protection, the basic requirements.

After a long round-trip charge-discharge test, collect relevant data, drawings, can be achieved without a balanced circuit waveforms comparing the experimental data are: the balance of the circuit of a hp PP2182D battery lithium and lithium 2 upper limit of the variation in battery voltage, such as that shown in Figure 6 and Figure 7, the ultimate balance of protection of lithium batteries 3 times the upper limit of battery voltage changes as shown in Figure 8, and balanced with the protection of batteries and lithium batteries 4 of 5 threshold voltage to change the battery of Figure 9 and Figure 10 shows the non-balanced circuit with 6 cells Lithium minimum voltage of the battery as shown in Figure 11. Figure 1, the points of all curves measured for the first time the limit of the battery (bottom) voltage, curve 2 points for long term running of the toshiba PA3395U-1BRS battery measured upper limit (lower) the voltage value.

On the accession of a balanced circuit the maximum voltage of the battery is maintained at an equilibrium point of 4.22V and 4.18V or more, effective protection of the upper limit of the battery voltage, non circuit to balance the maximum voltage of the battery which seems random, by virtue of membership of a balanced circuit the battery voltage level is maintained below the equilibrium point around 2.91V, the effective protection of the lower end of the battery voltage, non-balanced circuit limits the voltage of the battery which seems chaotic, badly damaging the battery life of the nature of coherence and the.

This departure from the practice of engineering, the dynamic nature of lithium batteries in a phase of high flow discharge occurred after the upper and lower limits of the phenomenon of unequal tension is proposed based on the balance of the circuit TL431, and lithium-depth study of a balanced circuit. Practical results show that the design and balanced on the balance circuit and the circuit not only ensures high speed of discharge of the battery after the battery requirements of consistency, but also effectively protect the battery voltage the upper and lower limits for the further study of high battery performance energy storage systems and hybrid systems for electric vehicles has laid a solid foundation.

1, the pricing of common sense

Here, we must first note that the load is an important step in the use of rechargeable batteries. Load appropriate and reasonable to extend the battery life is very good, while the random brutal life of the rechargeable Laptop battery will be greatly affected. On one side, said the current lithium batteries are based on the basic package of each product individually and not jointly, if different products to provide their own equipment for loading, and not common, when in service as long as you can use to follow their instructions. While it is the introduction of the battery refers mainly nickel-cadmium batteries and nickel-hydride batteries in metal.

The battery compartment on nickel and nickel hydride batteries, metal, there are two ways in which we are known as “fast charge” and “trickle charge”. Quick charge and trickle charge is the charge of an important concept, and only learned about the fast charge and trickle charge in order to properly grasp the load.

Firstly, the fast charge and trickle charge is a relative concept. Some people have asked, my charger with charge current of 200mA is not load quickly? The answer is not absolute, should have answered some batteries is fast charging, and some batteries, it is simply loaded slow. So how can we judge fast charge or slow charge it?

For example, a 5, Ni-MH power capacity IBM ThinkPad T41 battery of 1200 mAh, while the other section is 1600mAh. We have a battery capacity is called 1B, 1C see is a logical concept, the same 1C, are not equal.

During loading, the load current is less than 0.1C, we called the trickle charge. As its name implies, refers to the current very low. In general, the burden of maintaining the battery can be comprehensive without harming the battery, but the trickle charge to use the time spent far too long, so rarely used alone, but rather, and other pricing methods used in combination.

0.1C, 0.2C charge current between the two, we called the trickle charge. Load current is greater than 0.2C is less than 0.8c is a fast charge. When the load current is greater than 0.8c, we call it super-fast loading.

Precisely because the concept of 1C is a logical rather than absolute values, therefore, according to 1C slow conversion of the fast charge is a charge of relative value. Mentioned in the previous example 200mA charging current for Dell Inspiron 1420 battery 1200mAh fills slowly, but it is for the 700mAH battery fast charge.

Aware of the concept of fast and slow filling, we also need to understand the situation charger can charge the battery properly. Charger on the market can be divided into two types of constant current charger and automatic battery charger

2, constant current charger

Constant current charger is the most common chargers, nickel-cadmium batteries of the time we started to use the charger with constant current. Constant current chargers typically use a load current slow, its use is relatively simple, just put the battery in the battery can be charged storage. Note that the calculation of the charging time must be accurate.

The calculation of the charge time has a simple formula: Hour = 1.5C / load current. For example: on the charger 1200mAH hp Pavilion ZE2000 battery charge current of 150mA, then the time to 1800mAH/150mA equal to 12 hours. Of course, in many cases can not be calculated exactly the time we can choose the nearest half an hour to facilitate the chronograph. For example: charger current 160mA, right 1400mAH battery charging, then time for 2100mAH/160mA about 13 hours, instead of calculating the points.

Construction of a simple constant current charger, labor stability, is a good way to charge little effect on battery life. But it also has its limitations, we must first calculate the time, while nickel-metal hydride batteries with a capacity for growth, the constancy of the time course load required for longer and longer, the use of ’cause a number of drawbacks. Thus, in recent years, rapid charger system is also very popular

3 autoloader and quick

Fast automatic charger in these two years are always better received, he has the speed of loading, security and so on. But there are also some people have doubts about this because of the fast chargers are essentially using current fast charge to charge, the impact of these people will be scared about the life of the sony VGP-BPS5 battery. So the current situation?

Firstly need to be sure that the current charging high impact on the life of the battery is very low, and in many cases, we use fast charge and even ultra-fast load, the current load can sometimes reach 2C or higher. Mainstream is not a killer battery, the real impact on battery life is the heat capacity at high current generated during charging.

We charge the battery when using the nominal voltage above the battery voltage to make, but the battery itself, the load current produces a back EMF, it is part of the current to compensate the the back-EMF and in vain for power and transformed into heat. When the load current is larger, more electrical energy is converted into heat, charging the higher temperature. Too high a temperature on rechargeable batteries is harmful, and a slow charger with constant current, because it is slow charging, the heat generated within the control box, so no need to take special measures. But in the ADF rapidly using a fast charge current will generate high temperatures. Therefore, currently available rapid charger automatically have adopted various methods to reduce the load when the temperature, typically using the cosine law is not a constant current load, but it has intensity current wave of cosines The changes that will reduce heat buildup, thus controlling the temperature within a certain range. Since this type of charger is no longer using the constant load current, charger current is constant in the past, a clear distinction between

To use the quick charger Another problem is that when the charging time is counted if you forget to stop after charging damage the toshiba PA3284U-1BRS battery charger to be much larger than the current slow constant overload resulting damage. Therefore, to solve the problem of overload, voltage fast charger is generally used as the France and other methods to determine the slope to determine if the battery is nearly full, these chargers are used to control the circuit, or IC chip to perform this task. When the battery is almost full, the control circuit will automatically slow charge mode, trickle charge the battery. Used trickle charge current of the battery on the advantages are obvious, the one mentioned above, can trickle charge the battery charge very complete, followed by anxiety billing question, if the maximum use of chargers such advantage n is not obliged to go computing time. The specific use to consult the manual for instructions specific to avoid improper operation.

It is a branch of the fast charger is ultra-fast charger, line battery charger applications of these small, design, structure and processes are very complex, so the prices are quite expensive.

On special occasions, people need in a time short of a good rechargeable apple M8403 battery, which requires the use of ultra-high speed charger. As the ultra-fast charger requires a lot of load current, and some have even used the 2C-3C load current, the heating problem is particularly serious, just by using the cosine wave accusation is not enough, both of these chargers adopted a cosine wave in the post – Insert a landfill very short this approach. This approach can reduce the back-EMF due to the consumption charge current generated by the accumulation of heat, so an additional control of temperature.

4, discharge

Were introduced to a memory effect of rechargeable batteries, we also know that when the memory effect gradually accumulated, would be the actual use of the battery capacity has dropped significantly. To reduce the memory effect caused by the negative role of an effective discharge. In general, nickel-cadmium batteries because of the memory effect most obvious, it is recommended to use 5-10 times after repeated charge for a discharge, while nickel-metal hydride memory effect of batteries must be better, you can charge made after the use of 20-30 times per discharge.

On the market a number of high-end loader to carry out their functions, but the vast majority of feeder medium and low Aspire 3000 battery is impossible to perform functions, then how can we do? To understand the principles of the landfill, we can also try to have the battery discharge.

We already know that nickel-cadmium batteries and nickel-metal hydride battery nominal voltage is 1.2V, but in fact, the battery voltage is a change of values, the adequacy of electricity around the volatility of 1.2 V or more. Generally fluctuated between 1V-1.4V, different brands of batteries vary in regularity, the fluctuation of voltage is not fully consistent with

Discharge the battery is to use a low current discharge, the battery voltage falls slowly to 0.9V-1V between the discharge should stop. Not recommended under the discharge of the battery of 0.9V, it will cause excessive discharge, the battery is not irreversible damage, said on a rechargeable battery is not suitable for use in appliances to the remote, because the use of the remote being very low for a long period of the remote is easy to use cause an excessive discharge. Following a performance of the VGP-BPS9A/B battery, you’ll be pleasantly surprised to find the battery capacity has recovered its original level, so when the battery capacity has been found to decline, it is preferable to a landfill.

His discharge the battery so there is easy way to make a small bead like electric charge, but you must use the meter to monitor voltage changes, to avoid excessive discharge.

For the shipper to choose the shipper to choose fast or slow charger with constant current, which depends mainly on the orientation of their own use. Such as the frequent use of digital cameras and other equipment from a friend, you should choose a quick charger, to meet time requirements, and even ultra-fast charger, you can buy, but only the use of portable devices listening as a friend, a constant current charger will be able to meet the needs of

In controlling the correct charge and knowledge of the landfill, everything will be better able to use their own rechargeable batteries. Please do not adhere rigidly to a fast charge.