1. Advanced Measurement Technology: This lithium battery internal resistance tester employs a true 4-wire AC sine measurement, effectively suppressing the impact of test leads and contact resistance. This assures you of accurate and reliable readings, making it a vital tool for precise electrical measurements. 2. Functional Interfaces: The internal resistance test instrument comes with two functional interfaces, supporting battery sorting functions. This feature provides a streamlined process for battery management, making it a convenient tool for electrical tasks. 3. Built-in Battery and Power-Saving: This battery internal resistance meter features a built-in battery and supports mobile power bank charging. With its low power consumption and numerous power-saving options, it ensures long-lasting performance, reducing the frequency of recharging. 4. Wide Range of Resistance Measurements: The battery internal ohm meter supports testing up to 200 ohms, with a minimum resolution of 0.01 milliohms and less than 5 milliohms. By pressing the HOLD button, the ZR function is activated to measure small internal resistances as low as 0.30-0.50 milliohms. 5. Versatile Battery Compatibility: The true 4-wire 1KHz AC sinebattery ohmmeter operates within a range of 0.00001 ohm to 200 ohms. It can test a variety of batteries including lead-acid, lithium-ion, lithium polymer, iron phosphate lithium, alkaline, nickel-hydrogen, nickel-cadmium, button batteries, and more. With the ZR function, measurements below 5 ohms are even more accurate, ensuring precise internal resistance readings. Battery:1 x Lithium battery, 2000mAh (included) Range:1V/10V/100V Type:A:Upgraded Version Colour:As Shown Material:ABS Package Contents: 1 set * Battery Internal Resistance Tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.