With the wide application of Li-ion battery, the security issue is to attract attention. The lithium-ion detection parameters in real time allow to avoid unsafe use of battery, and can optimize the performance of the battery. Because of limitations in some applications difficult to determine policies, the need for remote monitoring of the battery, such as street lamps battery management, or because of the extensive use of online monitoring per connection is too many problems, such as base stations, power management, monitoring the condition of the battery, or a lot of radio stations in the communication concentration of occasions, we may collect through wireless network for transmission of data management. Hp laptop battery
The system is composed of the lithium-ion state data acquisition parameters, HP PB994A Battery, HP PB991A Battery, HP pavilion dv6000 Battery transmitting wireless signals, the data processing parts, the system diagram in Figure 1. Front by the acquisition module parameter status and module control transmitter, which comprises a data collection voltage lithium-ion battery, current, resistance and temperature parameters were measured The data sampling microcontroller initial treatment, and control of the chip emission modulation to send. Back-End Module control system by the wireless receiver, the microcontroller and the serial circuit, the local computer, the chip receiving signal demodulation, single chip to receive data and processed data will actually be transmitted via serial port on the local computer, supervisory staff may be on the state data analysis to control the operating status of the batteries, the batteries are not normally addressed in a timely manner to ensure the reliability of its work.
Lithium-ion battery in a variety of application environments and for system management, the state sampling device is modular by design, including: lithium-ion battery voltage measuring circuit measuring circuit, the circuit of the internal resistance measurement, the measuring circuit 4 room temperature [1,2]. Detection module signals collected A / D conversion, and the data sent to the control module. Designs used in high precision, high efficiency module data acquisition both general principles and special flexible configuration. SCM system may strobe on each control module, the module can be used alone can free combination, can adapt to different applications. HP PB991A Battery
2 experimental systems
Wireless data transmission and comparison of data transmission cable, which is characterized by use of the RF signal to send and receive data packets. Wireless data transmission primarily by the data terminal, wireless receiver, HP PB994A Battery, HP PB991A Battery, HP pavilion dv6000 Battery and the main component of the primary monitor, the main monitor and the main receivers use serial communication port. The transmission system is to achieve full status line lithium-ion monitoring this, and therefore the precision of the data in real time and energy consumption are key design.
2.1 Transmitter
2.1.1 Design and implementation of the transmitter circuit
Wireless transmission system launched by the end of the module data acquisition hardware key, the microcontroller chip and RF emission, the circuit of Figure 2.
The paper is Atmel Corporation AT89C51 MCU control of the launch system, MCU module control data acquisition have been the battery voltage, current, resistance and sampling temperature. wireless transmitter chip is the integration of the Nordic Norway presented chip wireless transceiver nRF401, nRF401 chip integrates high-frequency transmitter / receiver, PLL, FSK modulation / demodulation and switching multi-channel and other functions, in the low-cost digital communications applications wireless movement of technical advantages [68].HP PB994A Battery
2.1.2 Software transmitter
Based on how the lithium-ion battery monitoring system design, the software design process based on Figure 3.
Of the sample parameters lithium-ion battery is divided into several states: the sampling time of first, second, triggering samples, there are two types of triggering, there is at rest in the circuit Monitoring detects when the battery work in the current state of work began regular sampling, the other is the resistance of the sample triggering. Control module in the system does not work in off mode, MCU current operating system as an external trigger interrupt. Once the current system, the microcontroller to respond to break into the work mode. First set the sampling mode module, the parameters of the battery status of the sample, a delay to wait after sampling the microcontroller to read the sample data were analyzed to determine if the data sent, send the sample data is held in accordance with the specific application system may pre-configured in the MCU. Control system made the following adjustments:
(A) Monitoring system has been applied to four series Li-ion 5Ah line monitoring, the current operating system is 1A, the maximum current of 5A. The application site is a battery protection circuit, HP PB994A Battery, HP PB991A Battery, HP pavilion dv6000 Battery over voltage value of load protection 4.2V on the voltage discharge protection 3.3 V, the value of overcurrent protection 3A
(2) in the surveillance system to define the parameters of the battery of the normal range of working conditions: working voltage is 3.4V ~ 4.1V, 2.5A operating current temperature range -10 ℃ ~ 60 ℃, initial resistance value below 2 times; HP pavilion dv6000 Battery
(3) When the battery is in the normal course of work, the monitoring system at intervals of 60 years on the voltage, current, temperature, sampling time, after sampling 10 of 10 samples, then send the value of the arithmetic mean. Under the internal battery resistance under normal circumstances, by starting cycle sampling circuit 10 samples;
(4) If the battery status parameters beyond the normal scope of work, the sampling circuit in the fast sampling period, at intervals of 10 seconds on voltage, current, temperature, time of sampling, sampling value of 10 times the arithmetic mean value, and begin the battery internal resistance of the sampling circuit samples data within the group and send the sample
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