Feature: 1. True 4‑wire 1Khz AC sine battery internal resistance meter, with high sensitivity and accurate measurement. 2. The maximum resolution of internal resistance is 0.00001Ω, the maximum measurement range is 200.0Ω. 3. The maximum voltage resolution is 0.00001V, and the maximum measurement range is ±99.999V. 4. Test lithium battery voltage can be displayed to 0.0001V, all ranges can be used for positive and negative measurement of voltage. 5. It can measure lead acid, lithium ion, lithium polymer, lithium iron phosphate, alkaline, dry battery, nickel metal hydride, nickel cadmium, button battery, etc. Specification: Condition: 100% Brand New Item Type: Battery Internal Resistance Tester Material: ABS Internal Resistance Measurement Accuracy Format ±([Accuracy Percentage]+[Least Significant Digit]) Range Resolution Accuracy 20mΩ 0.01mΩ 0.7%+7 200mΩ 0.1mΩ 0.5%+5 2Ω 0.001Ω 0.5%+5 20Ω 0.01Ω 0.5%+5 200Ω 0.1Ω 0.6%+5 When the gear is within the range of 5%-95%, the error may be greater than the above accuracy when it is not in this range (less than 5% of the gear range, or greater than 95% of the gear range). Voltage Measurement Range Resolution Accuracy ± (% Reading +% Range) 1V 0.00001V 0.15+0.015 10V 0.0001V 0.15+0.010 100V 0.001V 0.15+0.015 Positive and Negative Symmetric Error ±(0.012%+5 Words) Within Normal Use Temperature (10℃-40℃), Temperature Drift 100ppm/℃ Battery Properties Lithium Battery Model 18650 Battery Capacity 2000 MAh . Package List: 1 x Battery Internal Resistance Tester1 x Clip1 x Probe Test Line4 x Needle1 x 18650 Testing Bracket1 x Manual Note: Read the manual and the instructions on the back of the instrument before use. It is strictly forbidden to input AC signals and DC voltages higher than 100V.