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.