Analysis of common problems and maintenance methods of lithium battery protection board

The 12v lithium battery is a voltage close to 12v obtained by connecting multiple 3.7v lithium batteries in series, and we have to use the 12v lithium battery protection board for the series connection of lithium batteries, which can protect the series lithium battery pack. When the lithium battery is overflowing, it can be used to equalize the voltage difference of each single lithium battery, and effectively deal with the loopholes in the series circuit. So how to repair the 12v lithium battery pack protection board when there is a bad abnormality? Here are some common problems of the protection board for decomposition and maintenance. 1. No voltage or abnormal voltage. If there is no voltage or abnormal voltage, we should adjust the multimeter to the DC 20V position, and then use the red meter pen to touch the positive pole of the lithium battery cell, and the black meter pen touch the negative pole of the cell. If it is a multimeter If it shows that there is no voltage or the voltage is very low, it proves that the battery is damaged. Pay attention to check whether the positive and negative poles of the protection board are reversed. If they are reversed, the charger is equivalent to forced over-discharge when charging the lithium battery pack. 2. There is no over-current protection. If there is no over-current protection and other phenomena, first check whether the circuit of the over-current test pin is defective, and replace the protection IC if there is any. 3. There is no resistance or the resistance is too large to be identified from the resistance pad The circuit will look for the reason, check whether the identification resistor is disconnected, whether the resistor is pasted incorrectly, whether there is a short circuit or an open circuit, etc. 4. If the battery cannot be charged, use the multimeter switch to select the 20v position, and then use the red meter pen to touch the positive electrode of the battery cell or the protection board. If the multimeter shows a voltage, we must decompose it according to the following conditions: Is there an output voltage? Is the cell voltage normal? If the above voltage is not normal, we can basically judge that the protection IC or MOS tube has been damaged. At this time, it is enough to replace these two components. 5. There is no internal resistance or the internal resistance is too large 1. If there is no internal resistance, check whether the pins of the MOS tube are damaged, and if so, just replace the MOS tube. 2. If the internal resistance is too large, then use a probe to contact the electric fish lithium battery protection board to test for reasons such as poor contact or excessive oxidation. Also check whether there are more nickel chips on the battery core. If the number of nickel chips on the battery core is too large, it will cause excessive internal resistance. The maintenance methods of the lithium battery protection board used above are basically through comparison, visual inspection, voltage measurement, and on-off detection. As long as these methods are mastered, I believe that you can proficiently repair the lithium battery protection board. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Analysis of effective methods for guarding against bulging of lithium batteries for electric vehicles