1 storage characteristics:
The full power of the state of lithium-ion battery kept at 20 ℃ under 28 days to maintain the capacity of the average rate of 96%, recovery rate was above 99 percent. 60 ℃ in the next 28 days preserve the capacity to maintain the rate of about 75 per cent, recovery rate of 90 per cent.
2 Life:
General battery capacity reduced to 60% of the nominal capacity of the rechargeable battery discharge known as the frequency of the service life, the life of lithium batteries, 500-1000.
3 charge:
Rechargeable batteries that rate the rate:
Charging rate (C) = charge current / PCGA-BP71A battery capacity
4 memory effect:
Refers to the use of batteries in the absence of a fully discharged on the charge, resulting in negative board does not have a normal oxide crystals, to charge the battery performance is adequate, but when the voltage discharge plunged, leading to shortened ThinkPad R50 battery life, lithium batteries nickel-hydrogen batteries No memory effect.
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01Sep
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01Sep
Just three years ago, gsm power amplifier solutions integration is far from ideal, transmission system solutions support the needs of different components of low-frequency, high frequency laptop battery and power control, input and output matching circuitry also need more than discrete parts, There is also the harmonic signal filtering, coupling capacitance of the power control function and for all the support components. At that time can not be achieved due to the integration process technology, simulation tools for high value for q (low loss) and the demand for passive components 3 gpp (gsm) specifications of the strict requirements. But in the past two years, has an external power amplifier solutions integrate functions and components for multi-chip module, makes the solution volume and complexity are greatly reduced. To the recent, new developments have power amplifier technology, low-cost and high-yield single solution began to emerge, further reducing the number of parts required for the design and complexity.
For design engineers, power amplifier performance measurement and comparison is never easy. As the improvement of functional integration, power amplifier effectiveness of the quantitative indicators are important re-definition ibm battery, to compare different integration of the power amplifier, the formulation of specifications and background has become equally important to their own specifications. This paper will analyse the two important power amplifier performance indicators, namely the power and efficiency, we will be in different integration and power control framework to analyze the information. In order to effectively compare two different integration of power amplifiers, antennas and batteries we will be as system solutions performance reference point, then they are merged into one indicator - the average sudden current (average burst current). These concepts as long as the slightly modified, can be extended to other radio frequency transmission system.
Power amplifier output power and antenna power comparison
For different integration or a different structure of the power amplifier, to assess their performance is the best way to specify ThinkPad R40 battery the antenna power requirements, and then calculate the power amplifier output power requirements. Generally speaking, the antenna power after the calibration standard in the low-frequency band (gsm) to 32.75 dbm, high-frequency band (dcs) compared with 29.75 dbm.
Transmission system used by the power control system will affect the power amplifier, antenna in order to meet ThinkPad T40 battery the requirements of the standard must have the power, the application of the most extensive power control structure is closed-loop power control, power supply voltage control and power supply current control
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01Sep
Portable electronic products to promote the rapid development of battery technology upgrading, including lithium-ion batteries with high energy density, high internal resistance and high laptop battery voltage and high frequency of circulation, low self-discharge rate, and other characteristics come to the fore, quickly becoming the mainstream.
Although lithium-ion batteries have all these advantages and good market prospects, it requested the charging circuit is relatively high, in the process of using to avoid the charge and discharge of a phenomenon. Lithium-ion rechargeable ibm battery the process as shown in Figure 1, in a charge cycle, the lithium batteries in the rechargeable battery testing required prior to the start of the voltage and temperature to determine whether the charge, if the battery voltage or temperature exceeded the permitted range, to prohibit the charge. Each section allows the battery charging voltage to 2.5 ~ 4.2 v, temperature of 2.5 ~ 50 ℃. The battery in a deep discharge of circumstances, must demand the charger during a pre-charge, fast charge the battery to meet the conditions, then the rapid battery manufacturers recommend charging the battery at constant current charging, the battery voltage slowly rise once the battery voltage To set the termination voltage (normally 4.1 v or 4.2 v), constant current end-of-charge, the charge current rapid decay, the charge into the full process of filling in over the course of charge, the charge current gradually decay, until sufficient time for overtime , The deadline for charging into the top; deadline for the top charge, a very small charger to the Pavilion DV4000 battery charge current supplementary energy; closing the top of charge for a period of time, close the charge.
Linear power supply output voltage vl reference voltage is two times, to provide for external load of the current 20 ma, and a short-circuit protection, pwrok (power-ok) for the provision of micro-controllers reset signals and inhibit the charge current.
High-precision voltage reference for the lithium-ion battery voltage to provide accurate Fu Chong, with an accuracy of 2 percent of the 20 k ω resistance connected to Fuchong voltage can be set up through an external resistance. Should have a one percent accuracy, because it has a direct impact on the accuracy of voltage Fu Chong, Fu Chong voltage accuracy of the lithium-ion Presario V2000 battery life and capacity play a decisive role.Voltage / current regulator by the high-precision attenuator, the voltage loop, loop current, the current detection amplifier components. Attenuator can be set up to pin voltage stability for a lithium battery voltage or two lithium battery voltage (voltage corresponding to 4.2 v or 8.4 v). Current detection test battery of high-end amplifier current, it is actually a transconductance amplifier, can be external restrictions on the flow resistance rcs voltage into current, and this current role in the external load resistance riset, by changing the rcs and can riset The charge current regulation, but also by ThinkPad R40 battery changing the voltage or the low end of riset increase / decrease iset end of the current adjustment. Voltage and current connected to the loop by the end of the cci ccv and external capacitor compensation correction, the output of the two loop through the logic “or” after the driver of an open-drain n-channel FET constitute the mos Active load, the external p-channel FET mos adjustment or pnp transistor components, together with other components constitute a complete circuit.