With a constant current source to charge the battery when the voltage is switching to a certain degree of positive slope up. This is due to the internal battery discharge and other chemical processes, polarization around the cathode to the accumulation of ions decreased. Therefore, the operating point depends on the battery charger to connect the length of time, and the history of battery life. With most electronic laboratory buildings to find the universal device load, to simulate the load model of this complex is difficult. Toshiba Tecra A3 battery Toshiba Tecra A4 battery
Require frequent testing of the load circuit, or system characteristics must be described in detail, the exact simulation of the process of recharging the battery is very useful. simulation process requires continuous scanning of all dash operating point. The results also show that analog circuits, so the operator can identify the problems and failures and interference. If the analog circuit can provide output voltage of the battery and signal, these results can be directly used as the signal of the oscilloscope. The tests will be accelerated (from a few hours to a few tens of seconds), and in accordance with need several Fanfu the real test of the battery is more convenient. However, accelerated testing to determine the charging power after the thermal side effects. Therefore, you may need additional time for testing of feed and control circuit in accordance with the thermal time constant.
The introduction of the load cell model
Figure 2 is a circuit simulation of the lithium-ion single. DC charger stage to end the charging voltage and fast charge current setting decision by the shipper. Simulator initialization can be set up under the internal battery fully discharge voltage 3V, but the tension can be increased to 4.3V, to test the overload condition. 3V initial value is usually used for a circuit voltage low battery shutdown (used to complete the process of lithium-ion battery discharge). This design specifically for pressure cancellation fee charger standard CC-CV 4.2V Li-Ion. The design of the adjustment is very easy to adapt to the termination voltage non-standard and complete discharge voltage of the test. Test on the charger up to 3A of current training simulation energy consumption by the limits of power transistor. Toshiba Tecra A5 battery Toshiba Tecra A6 battery
According to the parameters given, the charge current of 1A, the integral time constant to simulate the circuit 6-7 seconds to reach the charger 4.2V limit. On the beach at current strength, fully charge and discharge termination voltage to the analog voltage lithium-ion (in this case, the middle finger US18650G3 Sony) on the basis of parameters typical complete. The simulation of the battery voltage does not reflect the impact of ambient temperature.
shunt regulator shunt regulator design with MAX8515 and a pair of bipolar power transistors (selection of the regulator to examine the accuracy of its internal reference voltage), high transistor TIP35 currently installed in the radiator heat dissipation of 25W on.
MAX4163 Dual Op Amps, an amplifier to the load current integration, another amplifier to amplify the signal current measurement and prejudices. The op amp is a power ratio of high supply rejection, and supports full range swing input / output, which simplifies the design of two types of functional circuits. Note that with the positive battery terminal emulator 0.100Ω current sense resistor in series and the resistance of the internal battery. Toshiba Tecra A7 battery toshiba PA3191U-1BRS
In automated testing – based data acquisition system of work, may be an external signal to reset the simulation to fully discharge the battery status. Also, test set manual reset button is available.
Use the SPST switch can select the cell simulation in two modes. Take a side, the implementation of the emulator integrated charge, as described above. Throw B-side, the simulator will be secured to a fixed DC operating voltage at the test site charger output and current smoking. To achieve this functionality, “set” voltage can change the variable resistor 50kΩ between 5.75V to 2.75V manually set. These parameters are voltage and current of the internal inhalation. Measured voltage terminal emulator (Vbatt) equals the set voltage current flowing through the resistance simulation of the absorption cell (0.100Ω resistance) pressure drop. Circuit simulation of power from the battery when the charger output. apple a1281 apple a1245 apple a1008
Simulation of circuit performance
As can be seen in Figure 2 testing process: a fast charge current is 1A initial charge (curve B and D), the other is a fast charge 2A load current (curves A and C). In both cases, the first step in the charge CC until the battery voltage reaches the termination voltage is 4.2V. Afterwards, the current decay exponentially, while the simulation of the battery voltage remains unchanged. 2A charge current is terminated when the voltage reaches a shorter time, and should the same design. However, please note that the doubling time is not being half of the load wills only half the time CV mode, the test battery with the real case.
Conclusion
As the lithium-ion battery charging process takes an hour or more, using the actual load test lithium battery charger would be very tedious and often impractical. To speed up the battery charger test, this paper describes a simple circuit used to simulate the lithium-ion batteries. The circuit provides a non-use of lithium battery charger in a cost-effective screening. apple a1280 40y6797