Characteristics: 100% new and in high quality. This tester discharge is used do test the capacity of a 1,2-12 V battery. It is easy to use and powered by a micro USB power source. This tester discharge allows you to check the test capacity, voltage and current of the battery. Designed with LED LEDs indicating which parameter is displayed on the display. Specification: Power source voltage: DC4.5-6V (micro USB) Operating Current: 70mA Discharge voltage: 1,00 V-15,00 V, 0,01 V resolution Cut-off voltage range: 0,5-11,0 V Supported Current: 3,000A, 0,001A Resolution List of packages: 1 * battery capacity meter 2 * Resistors (5 W, 7,5 R) 1 set * fasteners Note: 1, the resistor load will heat up strongly during the discharge process, be careful. 2, to improve the accuracy of voltage measurement, this circuit is specially designed with DC polarity and will display a small voltage when do anything that does not affect the actual measurement. If you connect the input terminals (0 V) together, 0 will be displayed. Collocation resistance estimation method: According to Ohm's law, to estimate the resistance value divide the battery voltage by the expected discharge current; The resistor power selection is more than double the result, in which the battery voltage is multiplied by the expected discharge current. It is important to note that the voltage is higher when the battery is fully charged, and make sure that the current must not exceed 3,0 A if the battery is fully charged. For example, if you need to use 2 A do test a 12 V battery, then the resistor should be 6Ω 50 W. The voltage of a fully charged new 12 V battery is about 13,5 V, which corresponds to a maximum current of 13,5/6 2,25 A (less than 3 A), so it can be used. In addition, if you use the lamp bulb do test, then the current can only be less than half (1,5A), because the resistance of the bulb cold is low, the impact current is very large, too much current can burn the circuit directly. Instruction: 1. The measured battery should be charged first. 2. Correctly connect the battery do of the input terminals (positive do positive, negative do negative), the reverse input may cause damage to the circuit. Connect the load do positive and negative output, then power the meter with micro USB working power (do not use a desktop computer or laptop USB as a power supply), displays the battery voltage at this time. 3. The direct start test just press the "OK" button, then the meter will automatically develop the appropriate cut-off voltage according to the voltage of the fully charged battery, and then start testing after 3 times the display flashes. If you need to manually set the cut-off voltage, you can press the "" or "-" button when the ti shows the battery voltage. The cut-off voltage is displayed with the initial “P” and the resolution is 0,1V, press “OK” to start testing after setting. 4. The test data will be displayed alternately with discharge capacity (Ah), real-time discharge current (A) and battery voltage (V). When the battery voltage reaches the set cut-off voltage, the tester cuts off the load control switch and displays the capacity (Ah) and the fast flashing indicator light. The displayed capacity is the actual discharge capacity of the battery. Error code and meaning: Err1: battery voltage is higher than 15V Err2: battery voltage is lower than set cut-off voltage Err3: load discharge current is too large for battery or circuit internal resistance is too large Err4: current is too large (current is greater than 3,1A) Err5: Improper use or burned tester due to incorrect connection (current sampling or MOS control switch is burned) Secondary calibration operation: Press and hold three buttons and tester power at the same time to enter calibration mode. First, display the calibration save times, then enter do the formal calibration sampling program, which shows 0u0A;Connect the positive and negative input terminals, then press the “OK” button,the display will show J10u;Connect standard voltage 10,00 V DC do positive and negative input,and then press the "OK" button, the display will show J2.0 A;Connect constant direct current 2,0 A do negative output and negative input,And then press the “OK” button to complete the calibration. Tester will pre-check the calibration data if the calibration data is correct, display four calibration data alternately, and then exit; if the pre-check of the data is unreliable, it rejects the data and then terminates the action.