True 4-wire AC sine measurement, to effectively avoids the impact of test lines and contact resistance. Two functions interface, the old battery sorting function, low power consumption and a variety of power-saving options. Test range up to 200 ohms with a minimum resolution of 0.01 milliohms and less than 5 milliohms. Press HOLD to enable the ZR function to measure internal resistance as low as 0.30-0. 50 milliohms. Features: Voltage resistance with the screen at the same time measurement, measurement quickly and steadily. The minimum resolution of up to 0.01 milliohms, easy to test large capacity, high discharge rate low resistance battery. Range can be 200 ohms, can be measured button batteries, 9V laminated battery and other low-capacity small current high internal resistance battery. Voltage, internal resistance test function, respectively, with manual automatic range function. Automatic range switch stable and quick, the measurement shows 4 times per second update, the basic can be locked in about 1S time range stable display. HOLD function to help you lock the display, more convenient reading. Using dot matrix LCD screen. Size font combination, which clearly shows the measurement results, but also display rich content. 2 kinds of display mode. Normal mode with the screen display resistance and voltage, sorting mode shows the interna resistance voltage and the level of battery classification and counting. Has a three-level battery rating detection. By setting the voltage resistance rating, the battery can be grouped. Built-in charging management circuit. And can be set to 200mA and 400mA two charging current. Energy saving function. Can be set 5 - 60min shutdown delay. No operation and input, the ultra-delayed automatic shutdown. Can be set to 5-30min delay into low power mode. Specifications: Material: plastics Voltage measurement: 4V/40V Maximum resolution: 1mV/10mV Accuracy: 0.8%+5/0.8%+5 Display mode: 4.400V/44.00V Internal resistancemeasuring ranges: 20m/200m/2/20/200 Maximum resolution: 0.01m/0.1m/1m/10m/0.1 Accuracy: 0.7%+7/0.5%+5/0.5%+5/0.5%+5/0.6%+5 Display mode: 22.00m/220.0m/2.200/22.00/220.0 Battery: 3.7V, 2500mAh Package size: 120 * 60 * 40mm / 4.7 * 2.4 * 1.6in Package weight: 300g / 10.6ounce Packing List: 1 * Internal Resistance Test Instrument