digital batteries

Firstly, brief history of the development of mobile battery technology

With 3G networks in the accelerated process of global business, 3G users also appeared to grow substantially. Technically advanced enterprises 3G has a unique appeal, prompting users more often use a variety of multimedia services. Short period of 10 years, only to have a phone call from cells of all functions to be transformed into a variety of functions in one portable device. At the same time, the battery of mobile phones has grown complex and changes.

Early in the era of analog phones, batteries account for almost half the weight of the cell body also totaled 2 / 3 ratio. This undoubtedly affected the portability of cell phones. At that time, the batteries of mobile phones can be divided into three types: batteries nickel cadmium, nickel metal hydride and lithium-ion batteries, IBM ThinkPad T43 battery  IBM ThinkPad T60 battery.

Nickel-cadmium battery is composed of two plates, one with nickel hardware, and other materials system with cadmium, these two metals in batteries can produce reversible reaction, so that the battery can be recharged. Its greatest feature is firm, and talks long. The first “Big Brother” is the use of nickel-cadmium batteries.

Also known as green nickel-metal hydride batteries, because it contains no metal cadmium, do not pollute the environment. Its power reserve of more than nickel cadmium batteries for more than 30% to 50% of talk time and mobile phone can be extended by 30%.

Lithium-ion battery is a battery of high energy density, which, with the same size nickel-cadmium batteries, the batteries in nickel metal hydride over a larger reserve of power, lighter weight. Lithium-ion battery or a smart battery, it can be a smart charger dedicated to “speak” to achieve the shortest charging times and the highest cycle life and Dell Inspiron 8600 battery  Dell Inspiron 9200 battery capacity.

While mobile phones and small light weight to improve the performance of the development trend of mobile phone battery nickel-cadmium batteries of the transition at the beginning of the main phase of nickel metal hydride-based. With the rapid decline in the cost of lithium batteries, mainstream mobile phones currently on the market have been primarily using lithium-ion battery. Because the lithium Slim secondly, because the lithium batteries have greater capacity, greater density of power output, load faster.

In 2003, the use of lithium up to 90% (about 650 million group of demand) in 2004 increased to 94% (about 758 million group calls). Because there is no strong threat to short-term substitutes, if 2 ~ 3 years, lithium batteries can still maintain its edge in the market for mobile telephony is expected to 2005, the rate of ‘use will increase to 98%.

2, cell phone lithium battery of technological change

Lithium F3172A PB995A batteries for mobile phones mainly in liquid-based lithium-ion batteries, the recent development of lithium-ion cell phone battery should be around two main aspects:

First, the traditional liquid lithium-ion battery materials in positive and negative electrodes, electrolyte improvements. The increasing diversity of functions of mobile phone battery performance right to advance higher standards, has developed a new battery electrode materials will in future lithium-makers ion batteries for some time being competition. Currently, Japan Sanyo, and Sony took advantage of Ni, Co, Mn 3-component materials to produce high-capacity battery 4.4V, while the cathode active material Li (NiCoMn) 1/3O2 Honjo, at Japan, the company was sold, the cost of these materials LiCoO2 is approximately about half, therefore, their application will lithium batteries, especially lithium-Powered Battery to reduce the price of a degree.

Secondly, polymer lithium-ion batteries in cell phones will gradually increase the proportion of applications and will gradually replace the traditional Li-ion batteries, but before the launch of 3G, it is difficult for traditional lithium-ion batteries provide a threat.

Because lithium high energy density-ion battery, the overload condition, the increase in battery temperature, the excess energy, the PA3191U-3BRS PA3285U-2BRS battery internal pressure increases the risk of spontaneous combustion or explosion. Lithium batteries are generally liquid steel or aluminum for packaging, the battery of huge explosions.

In traditional liquid lithium-ion batteries lithium polymer developed from the battery (hereinafter referred to as poly-lithium battery), just be able to catch the performance of non traditional lithium batteries. Firstly, thank you film composite aluminum flexible packaging, as opposed to the hard shell packaging in terms of conventional lithium batteries, is not easy to explode, with more security. Secondly, poly-lithium batteries are lighter, thinner and higher capacity. Thirdly, in principle, poly-lithium battery can be designed in any shape, for cell phones and other mobile devices designed to provide excellent condition. Fourthly, the poly-electrolyte lithium battery using the gel or similar solid material, does not leak, thus reducing pollution.

This polymer lithium-ion battery energy density and load-discharge time, with lithium batteries traditional liquid are basically the same, its benefits are mainly reflected in the size and shape can be arbitrary. Poly-lithium batteries is difficult because of performance and price of ordinary lithium batteries caused by strong shocks, the current poly-lithium batteries accounted for 12% ~ 13% market share. However, as manufacturers continue to join, the price of lithium-polymer continues to decline, polymer lithium-ion battery in the current lithium-ion battery is a matter of time.

Introduction

Although the extent of the tension has been used in many portable products separately estimate the remaining power of battery, but this way there may go up to 50% margin of error. The Laptop battery voltage and current will be the relationship between discharge rate, temperature and aging of the battery varies. For example, compared to the same power consumption, low flow, high throughput lead to greater pressure drop. When the battery is discharged at different temperatures, we can see similar characteristics.

With a long running time of increasing demand for products, system designers need a more accurate solution. In a wide range of levels of power demand, gas use battery gauge IC to measure the flow into or out of the battery, get better battery life estimation method.

Principles of battery fuel gauges

Battery fuel gauge is a kind of IC power control system of the battery, making power management system to report on the control processor. Good battery at least takes some steps to monitor the battery voltage, the battery temperature and current methods, a microprocessor and a Dell Latitude D520 battery of evidence of surveillance methodology.

Bq2650x and are complete bq27×00 battery fuel gauge, which is one for voltage and temperature measurements of the ADC (ADC) and a current and a load sensing ADC. The battery meter gas also has a battery monitor to perform calculations microprocessor internal IT. These algorithms will have lithium-ion (Li-ion) batteries self-discharge, aging, temperature and flow rate to compensate. The microprocessor allows the host system processor, without an endless calculations.

Battery fuel gauges offer such as “excess state power” and other information at the same time bq27×00 system also provides execution “surplus time” information. The host at any time that such information could be Asked by the host to decide yes or adoption of the LED screen displays the message to inform customers about the information of the battery. As the system processor requires only 12C or communication HDQ-led, whether the use of fuel gauge of the hp PB994A battery is very simple.

Battery Pack Circuit description

Figure 1 describes the battery in the circuit application. According to the IC gas meter to the battery packs of different batteries have at least three to four are available outside the terminal.

Figure 1 Typical Application Circuit

VCC and BAT PIN to access the battery voltage to the power IC and measures battery voltage. A low resistance value of meaning is installed in the ground terminal of the battery, so the voltage across the sense resistor can be gauges fuel drums in the control of high input impedance to the SRP and NRS. The current flowing through the sense resistor will help us determine the amount of the battery is charged or discharged. Resistance value within the meaning of choice, designers must take into account both ends shall not exceed the voltage of 100mV. The resistance value is too low in the low current conditions may lead to errors. Circuit board layout should ensure that the SRP and SRN to the sense resistor connected as close as possible endpoint for different sensors; this regard Kelvin measurements.

HDQ / SDA and SCL pins are open drain devices, both of which need external pull-up resistor. This resistance must be at the host side or on the side of the main claim, so that the VGP-BPS9/S battery meter to check the operation of sleep in the battery pack and portable devices can be activated after disconnected. Recommended pull-up resistor value of 10K.

Battery authentication

Portable devices, rechargeable batteries must be replaced before the end of life equipment. These offer cheap alternatives to the manufacturers of these batteries have opened a huge market, and these cells may not be a manufacturer of original equipment for security and protection circuits.

Thus, in addition to the features of cell battery gas gauge may also include authentication features (see Figure 2). Host will check that the calculation takes account of cyclical redundancy check (CRC) IC (TI bq26150) battery. The CRC on the authentication database and in the definition of IC in the secret above the CRC polynomial. Home also calculate the CRC, and a variety of value compared to determine if it has been verified. If not, then the host decides to conduct a validation or does not allow the battery systems.

Once the battery through the validation, then the bq26150 will receive the order, to ensure that all lines through the data communications in the host and the fuel gauges of the battery must be transmitted between the two.

This point of view, the host may continue to use the gas from the battery gauge. In disconnecting the battery and re-connected to the batteries must be repeated throughout the audit process.

2 cellular applications

Figure 3 shows the support of two with bq26500 Li-Ion battery typical application circuit. An adjustable voltage regulator was added to the system to achieve the multi-battery. Battery fuel gauges BAT pin is connected to the bottom of the anode of the battery to achieve regulation of measuring the battery voltage.

Host needs fuel gauges measured the battery voltage regulator battery explained that in determining the discharge end of the extinction threshold and cooldown. We can follow the reports of fuel gauge to the battery as the use of “state of surplus electricity and other information.

Conclusion

bq2650x and battery manufacturers bq27×00 offers a simple alternative to the report of the battery. Just from the records of gas from the battery meter to read the data, the host will receive the value of the remaining capacity, then the results displayed to the user. The use of fuel gauge of the battery, end users may be rare in the case of electricity whenever possible by using the loading capacity of the battery as electricity is estimated at more than toshiba PA3285U-2BRS battery voltage is measured only by the available data more accurately. Battery fuel gauge may be used in a variety of structures, which has an audit function, and allows, in many two battery-powered applications to use.