Several cases of abnormality in mobile phone lithium battery protection board.
1. No voltage or low voltage, no load
Poor battery cell voltage: test whether the self-consumption of the battery protection board is too large and the battery cell voltage is low.
The circuit of the battery protection board is blocked: for example, the MOS tube, IC components are damaged, the circuit is blocked, the components are soldered, fake soldered, and the via is blocked.
2. Large internal resistance
Test whether the MOS tube is abnormal, such as abnormal welding, MOS tube rupture, and use a multimeter to test the resistance of the MOS tube.
When the internal resistance of the MOS tube is relatively stable, test whether the internal resistance of the components such as fuse or ptc has changed, and then check whether the resistance value changes due to the micro-break of the via hole between the pad of the battery protection board and the component surface Big.
3. No short circuit protection
The over-discharge protection, over-current protection, and short-circuit protection use the same MOS tube. An abnormal short circuit indicates that the MOS tube has a problem, and there is no over-discharge protection function. It may also be caused by the abnormal soldering between the resistor and IC and MOS tube or the poor configuration of IC and MOS tube.
4. ID abnormal
Welding, cracking, or failure of the resistance material will cause the ID resistance to be abnormal, and the ID via is not conducting or the internal circuit is defective.
The performance test methods of mobile phone lithium battery protection board include NTC resistance test, identification resistance test, short circuit protection test, self-consumption test, etc. The test will use multimeter, tester, high-current needle holder and other tools, the purpose is to make the mobile phone lithium The battery protection board test is more accurate. Among them, the high-current needle holder can choose the shrapnel micro-needle module, which can not only transmit high current but also has a good connection function, which can provide protection for the test of the lithium battery protection board of the mobile phone.
The shrapnel micro-needle module has strong electrical conductivity, can transmit current in the range of 1-50A, and the overcurrent is stable without attenuation; the high-precision characteristics make it a good response method in small pitches, and the minimum can adapt to 0.15mm The pitch value can maintain a long-term stable connection, and it is not easy to card PIN or break the needle. In the mobile phone lithium battery protection board test, it also has an average service life of 20W. It does not need to be replaced frequently, which is beneficial to save time and cost. The shrapnel head has a self-cleaning design to avoid interference from impurities and is beneficial to the stability of the test.