The capacity of a lithium battery refers to the amount of electricity it can hold. The unit is usually “ampere-hour” or “milliampere-hour.” For example: the capacity of a lithium battery is 500 mAh, which means that if the battery current is 10 mA in operation, it can work continuously for 50 hours.
Lithium battery capacity test is based on full charge voltage and termination voltage set as parameters. Since the minimum discharge voltage of the lithium battery is 2.75 V, therefore a voltage lower than 3 V makes no sense. Lithium battery testing; Fixed current discharge is generally expressed in C, and lithium batteries are generally tested with a discharge of 0.5 C.
1. Fully charge the battery. The voltage of a single lithium battery after full charging is 4.2V;
2. Use a multimetere to find a constant current of 0.5C; lithium battery. Compared to the battery In terms of capacity discharge, the final voltage is set to 3V;
3. Multiply the constant current discharge time by the discharge current to obtain the battery capacity; constant current discharge cannot reach two hours, then the standard It is not enough to say the voltage, and the lithium battery may be counterfeited.
After the lithium battery capacity test is completed, performance tests, electrochemical tests and other items should be carried out. During the testing process of 3C lithium batteries, battery test modules and high-current shrapnel microneedle modules can be carried out. be used as connections. The conductive bridge can transmit large currents of 1-50A, and its performance is stable and reliable, which is conducive to stable testing.
To detect whether the 18650 battery is damaged, the method is as follows:
1. Check the label of the 18650 lithium-ion battery to confirm that its output voltage is 3.7V, but the capacity may be higher or lower than 2000mAh (some are 3000mAh)
2. Look for the positive and negative terminals of the 18650 lithium-ion battery. The shape of the battery's protruding round button is. the positive terminal of the battery, and the flat bottom position is the negative terminal.
3. Use a multimeter to check the output voltage. Make sure it is set to measure voltage. Place the small metal rod at the end of the red cable onto the positive terminal of the 18650 lithium-ion battery. Place the metal rod at the black end of the multimeter onto the negative terminal of the battery.
4. Display the multimeter display panel. If the battery is in normal condition, it should read between 3.6 and3.7 V. If the reading is below 3.5 V, fully charge the battery. If it is still below 3.5V after charging, that means you need to replace it, as these are signs that the battery charge is slowly diminishing.
5. Check the battery capacity, set the multimeter to measure the amount of current flowing per hour, and place the two metal rods on the positive and negative metal ends of the battery.
6. Check the multimeter display. The mAh of a fully charged 18650 Li-ion battery as labeled indicates that the battery is in good condition.