How to test the internal resistance and capacity of lithium batteries?

Lithium battery internal resistance test method: According to the physical formula Ru003dU/I, the test equipment forces the lithium battery to pass a large constant DC current in a short period of time (usually 2 to 3 seconds) (currently 40A to 80A are generally used). High current), measure the voltage across the lithium battery at this time, and calculate the current internal resistance of the lithium battery according to the formula. 1. Measure the open-circuit voltage of the battery: U12, a fixed resistance resistor in parallel at both ends of the battery: R, to discharge; 3. Measure the voltage at both ends of the battery during the discharge of the lithium battery: U2; 4. Calculate the internal resistance of the battery: ru003d( U1-U2)/(U2/R) Lithium battery capacity test method: Lithium battery capacity test takes full charge voltage and set termination voltage as parameters, because the minimum discharge voltage of lithium battery is 2.75V, so it is less than 3V The voltage of is no longer meaningful for lithium battery testing; the fixed current discharge is generally expressed in C, and the lithium battery is generally tested with 0.5C discharge. 1. Fully charge the battery, the voltage of a single lithium battery after being fully charged is 4.2V; 2. Use a multimeter to make the lithium battery a constant current of 0.5C, and discharge the battery in relation to the battery capacity, and set the termination voltage to 3v; 3. Multiplying the discharge current by the constant current discharge time is the battery capacity; check: if the constant current discharge cannot reach two hours, then the nominal voltage is not enough, and the lithium battery may be counterfeit. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: What methods can prevent lithium batteries from catching fire?