Forced discharge detection and overcharging detection

UN38.3 certification for forced discharge testing is mainly aimed at evaluating the ability of rechargeable batteries or original batteries to withstand forced discharge conditions. The method is as follows:

1. Each battery must be connected in series with a twelve volt DC power supply at ambient temperature and subjected to mandatory discharge at the same starting current and maximum discharge current given by the manufacturer.

2. The calculation method for the given discharge current is based on a resistor load of appropriate size and a test battery connected in series. The time for each battery to be forcibly discharged should be the same as the value of its calibrated capacitance divided by the initial test current.

3. For rechargeable batteries or primary batteries, if there is no combustion or disassembly within seven days after the test, it indicates that they meet the UN38.3 certification requirements.

UN38.3 certified overcharging detection is a test that evaluates the ability of rechargeable batteries to withstand overcharging conditions. Its specific method is:

1. The tested battery undergoes a 24-hour charging test under the condition of maximum continuous charging current.

2. When the charging voltage is less than eighteen volts, the minimum voltage tested should be twice the maximum charging voltage of the battery pack or the smaller of twenty-two volts.

3. If the charging voltage is higher than eighteen volts, the minimum voltage for the test should be 1.2 times the maximum charging voltage.

4. If the tested battery does not experience any ignition or disassembly within seven days, it indicates that it meets the testing requirements for recharging.

When conducting UN38.3 certification, the detection of overcharging and forced discharge of batteries must be carried out in accordance with the prescribed operating requirements, and if the test results meet the requirements, it can be considered as passing the test.