The so-called trade-in is just adding some repair fluid?

1) How to distinguish old batteries?
Check whether there are welding or used traces at the joints, or whether the casing is clean. The old batteries will always be used after refurbishment. In addition, when replacing a new battery, first check the packaging of the new battery to be replaced, and it is best to check it yourself before unpacking. Before sending the electric vehicle for repair, you must understand the models of the electric vehicle battery, motor and corresponding accessories, and check it when the repair is completed.
2) How to use electric fat bicycle meters correctly
Electric fat bicycle have been basically popularized in China. As the basic components of electric vehicles, how much do you know about how to use them correctly?
1. Frequently wipe the surface of each electric vehicle instrument. On the one hand, it prevents dust and oil from entering the instrument and damaging the watch core. On the other hand, it is also convenient to observe the movement of the indicator pointer.
2. Grasp the performance of each instrument and the relationship between the indicator status and the operating status of the relevant parts of the engine, so as to judge the operating status of the engine according to the indicator status, and find the fault location and cause.
3. When the engine is started, it is necessary to observe the dynamics of the various instruments, find abnormalities, and deal with them in time; while the engine is running and the car is running, the dynamics of the various instruments should also be frequently observed in order to grasp the working conditions of the relevant systems.
4. Meters with different voltage values ​​shall not be substituted for each other except ammeters to avoid damage to the meters.
5. The sensor performance of electrothermal and electromagnetic instruments is completely different. For example, the resistance value of the variable resistance sensor of the electric fuel gauge decreases as the fuel level of the fuel tank increases, while the resistance value of the variable resistance sensor of the electromagnetic fuel gauge changes on the contrary; The variable resistance value decreases with the increase of oil pressure, and the change of the variable resistance value of the electromagnetic oil pressure gauge is just the opposite; the thermistor of the electrothermal water temperature meter sensor has a resistance value of 220 ohms at a water temperature of 50 ℃ , The water temperature drops to 20 ohms at 115°C, while the thermistor of the electromagnetic water temperature meter sensor has a higher resistance value when the water temperature is 100°C, and the resistance value decreases significantly when the temperature continues to rise. Therefore, electric heating and electromagnetic electric vehicle meters and their sensors should be used together, and they should not be used interchangeably or replaced separately.
6. The water temperature meter sensor must be well grounded, and the wire of the sensor must not be grounded or short-circuited to avoid damage to the water temperature meter.
7. When installing the oil pressure sensor, the "↑" mark should be upward, otherwise the accuracy of the oil pressure gauge indication will be reduced.
8. The lower terminal of the electromagnetic fuel gauge should be connected to the sensor, and the upper terminal should be connected to the ignition switch. Otherwise, the pointer always points to "0".