Features 1、LARGE LCD DISPLAY: 3.2 inch 55x57mm TN color high definition LCD screen, providing textured display. Automatic switching of resistance and voltage range, simultaneous measurement and synchronous display. 2、TESTING RANGE: The voltage range is DC0.00V to ±120V, the internal resistance range is 0.000mΩ‑500Ω, 6 levels resistance automatic switching. Suitable for measuring all batteries within 120V and 0‑3000AH. 3、ACCURATE MEASURING: The tester adopts 1KHz AC low resistance measurement and noise reduction technology, and can measure under the running state of the object. 4 line Kelvin testing method to avoid the influence of wire resistance and contact resistance. 4、CONVENIENT TO USE: No need to distinguish between positive and negative poles during use, plug and play. Equipped with universal DB9 interface, it facilitates users to connect to various battery universal testing devices. It also has a battery filtering function. 5、LIGHT AND BATTERY: With backlight screen display and top LED flashlight lighting, it can operate normally even in dim environments. Equipped with a built in 1250mAh lithium battery for power supply, it can last up to 10 hours of operation. 6、WIDE APPLICATION: This battery internal resistance tester is suitable for acid battery, lithium battery, NiCd battery, alkaline battery, etc., for AA, AAA, button battery, 6F22, etc. Suitable for motorcycles, cars, trucks, boats, RVs, ships, etc. 7、EXCELLENT MATERIALS: The battery internal resistance tester uses TPR (thermoplastic rubber) and ABS materials, with a thickened design, impact and erosion resistance, providing comprehensive guard, greatly improving service life. Specification Item Type: Battery Internal Impedance Tester Product Model: IR502 Screen: 3.2 inch TN Color HD LCD screen with Auto Shutoff Function Battery Types: Acid Battery, Lithium Battery, NiCd Battery, Alkaline Battery Voltage Range: 0.00V to ±120V Impedance Range: 0.000mΩ to 500Ω Maximum Input Voltage: DC120V (no need to distinguish positive and negative poles), Cannot Input AC Current Range: 50mA-50uA AC Measurement Speed: 3 times/second Measurement Signal Frequency: 1KHz Voltage Range Test: Auto or Manual Selection Resistance Range Test: Auto or Manual Selection Test Method: 4 Line Kelvin Testing Method User Self Calibration: Support Factory Reset: Support Lighting Function: Support Battery: 1 x 1250mAh rechargeable lithium battery, continuous working time up to 10 hours (built in battery) Package List 1 x Tester 1 x Test Cable 1 x USB Cable 1 x User Manual 1 x Storage Bag