Yes, it is necessary for lithium battery. Since lithium battery is hazardous goods and may cause leakage or fire if misused. PCM and BMS is a necessary method to protect the battery from over-charge, over-discharge, over-current, over-temperature and short circuit. BMS also has functions of SOC(state of charge), SOH(state of health), communication and LCD screen etc.
Short circuit or open circuit of the connector or wrong connection, desoldering or cold solder joint between the batteries and lead, wrong connection between the batteries.
- The battery is zero voltage or there is battery with zero voltage in the battery pack.
- There is wrong connection inside the battery pack.
- There is abnormity of electronic components and/or PCB inside the battery pack.
- There is failure in charger.
- Outer element causes the charging efficiency to be too low, such as extremely low or high temperature.