Make sure that the thick black wire goes to the negative of the battery and the thick red wire goes to the negative of the load. (Note that the wiring of discharge and charge is different, see the concept of charge and power supply after Z) (The meter head uses the original imported chip, which has undergone very strict testing and calibration when leaving the factory to ensure that there is no quality problem before leaving the factory. When the current shows 0, 99.99% of the wiring is wrong, please be patient and check the wiring carefully) The current display is inaccurate: If it is a direct power supply or an independent power supply, and the power supply of the device shares the same ground, it is enough disconnect the thin black wire. Connect the power supply does not display: Any rectified AC power supply must be filtered by an electrolytic capacitor of more than 1000uF before it can supply power to the meter. Judge whether the header is good or bad (the following are two cases of normal header) Do not connect the shunt, connect the thin red wire and the thin black wire to the power supply, the meter with a range of 50A displays 50.0~59.9, and the meter with a range of 100A displays 100~109; Connect the shunt, connect the thin red wire and the thin black wire to the power supply, the meter with a range of 50A displays 0.00, and the meter with a range of 100A displays 0.0; Other notes: The measured current can only be connected to the negative of the power supply and the negative of the load. Voltage range: The power supply voltage range of the 5-wire meter head is 4-28V, that is, the voltage connected to the thin red wire cannot exceed 28V. Specification: Voltage measurement range: 0.0V-100V Current test range: 0-10A, Power supply range: 4-30.0V Voltage error: 0.1% Current error: 1% External shunt specification: 75 milliohms Working current: