Battery charger and battery test and measurement

1. Battery charger test After the rechargeable battery is discharged, it needs a charger to charge. A good charger should be able to provide a constant current for charging, and automatically stop charging when the battery is full, so as to maximize the battery life. The Boji electronic load launched by Ocean Instruments provides a very good battery charger test solution, which can be used to simulate the voltage and load form of nickel-cadmium, nickel-metal hydride and other batteries. Typical nickel-cadmium or nickel-metal hydride battery charging characteristic curve:

During the charging process, when the battery terminal voltage begins to drop (-△V negative voltage slope), the battery charger should stop charging. Overcharging the battery will cause permanent damage to the battery. When testing the battery charger, you can use a real charging battery test, but this method takes a very long time and is not practical or cost-effective. When using an electronic load, you can set it to a constant voltage load mode and set the required terminal voltage. At this time, the electronic load will draw enough current to control the voltage to stabilize to the set value. For example: to test a 1.2V rechargeable battery, set the terminal voltage from 1V, 1.2V, 1.4V, and 1.5V to test the current regulation of the battery charger, and then set 1.48V (-△V simulates a full battery) to test whether the charger will stop charging.

When using the Boji 3302 frame and 3310D series modular electronic load launched by Ocean Instruments, the voltage/current meter on the panel can directly display the terminal voltage and charging current of the battery charger. The five sets of memory settings can set up to five different terminal voltages to meet the test needs of convenience and repeatability. Note: The actual output voltage of the rechargeable battery may not be 1.2V, but a multiple of 1.2V.
2. Battery discharge test Any battery can be regarded as a voltage source, and its storage capacity unit is mAH or AH. For example, the battery capacity of 12V 6AH means that it can work for six hours at 12V and 1A output. When testing the discharge characteristics of the battery, the constant current mode of the electronic load should be used, and the battery should provide the test current within the required voltage range and within the specification time. Use a computer or printer to monitor the voltage and current of the battery. The constant power mode can also be used to test the discharge characteristics of the battery. When the electronic load works in the constant power mode, the electronic load will draw the set power value from the battery. At this time, the current of the electronic load will automatically increase as the load voltage decreases to keep the power constant, and vice versa. The Boji 3310A series electronic load launched by Ocean Instruments (62178811) can be combined with a computer to achieve constant power mode. Use a computer to read the load voltage and calculate the current at constant power according to the following formula to meet the constant power test requirements: Load current = set power ÷ load terminal voltage. (For discussion of this article, please contact Ocean Xingye Technology Co., Ltd., Tel: 62178811) 3. Battery charging test The Boji 3310A series electronic load launched by Ocean Instruments can be used to test the charging characteristics of rechargeable batteries. Generally, a DC power supply with constant voltage and constant current output can be used to charge rechargeable batteries, or a DC power supply without voltage regulation and current limiting (such as a simple rectifier and capacitor filter circuit) can be connected in series with a DC electronic load as a current source to charge the battery. At this time, the charging current is determined by the set current value in the constant current mode of the electronic load.