Power lithium battery temperature problem

　　1. Thermal management fault;

　　Heating failure (heating board); when the temperature is lower than a certain value, the heating is not turned on when charging.

　　Failure reason: heating relay or BMU failure; (2) heating plate or relay power supply circuit is abnormal.

　　Treatment: repair or replace the heating relay or BMU; check and repair the power circuit.

　　(2) Cooling failure (fan); when the temperature is higher than a certain value, the fan does not work.

　　Causes of failure: fan relay or BMU failure; fan or relay power supply circuit is abnormal.

　　Treatment: repair or replace fan relay or BMU failure; check and repair abnormal power supply circuit.

　　2. High temperature: One or more temperature points in the battery system are too high and reach the alarm threshold during operation or charging.

　　Causes of failure: temperature sensor failure; (2) LMU fault; (3) abnormal local heating of electrical connection; (4) fan does not turn on, poor heat dissipation; (5) close to heat sources such as motors; 6. overcharging.

　　(1) Measure the resistance value of the temperature sensor and compare it with the displayed value. If the actual value is lower than the displayed value and is the same as other temperature values, calibrate the LMU temperature value with the actual value as the standard; (2) Tighten the electrical connection points and remove foreign objects at the connection points; ensure that the fan is on; (4) New Increase insulation material and heat source isolation; (5) Suspend operation and cool down; immediately stop charging; I want to replace LMU.

　　4. Voltage jump: a single voltage jump occurs when the vehicle is running or charging.

　　(1) The connection point of the voltage acquisition line is loose; (2) The fault zone.

　　Solution: Tighten the connection point; (2) Replace LMU.