This product support independent 4 channel internal resistance, capacity measurement. Adopts direct current two-wire method to test internal resistance, with high accuracy of value when the battery is fully charged. Support separate charging, separate discharging, automatic mode supports up to 9 charging and discharging cycles. 18650 battery holder uses compact battery holder for flathead battery measurement. Features: The product supports four-channel capacity and internal resistance measurement, each channel is independent of each other, set up separately and run independently without interfering with each other. Adopts direct current two-wire method to test internal resistance, with high accuracy of value when the battery is fully charged. Support separate charging, separate discharging, automatic mode supports up to 9 charging and discharging cycles. Full automatic cut off charging, discharge to reach the conditions automatically stop, automatic mode 1 ~ 9 times adjustable cycle. Stop discharge voltage: 2.5V, 2.6V, 2.7V, 2.8V, 2.9V, 3.0V, 3.1V, 3.2V, 3.3V, 3.4V, 3.5V, a total of 11 adjustable gear. Digital display, real-time voltage, real-time current, cumulative capacity, cumulative energy, battery internal resistance, cumulative runtime - hhh:mm:ss (hours:minutes:seconds), cycle times, stop discharge low voltage, working mode menu, status indication, channel indication can be seen at a glance. 18650 battery holder using compact battery holder, suitable for flat battery measurement. Fan active heat dissipation, support overheating protections. Support Chinese and English interface switching, the default language is Chinese. Note: does not support the charging of lithium iron phosphate batteries. Specifications: Operating voltage: 5VDC Applicable battery: meet the stop discharge voltage 2.5 ~ 3.5V, 2.8V starts ~ 4.2V full battery are applicable Power supplying interface: two Type-C interface System language: English / Chinese switchable Test quantity: 4-channel charging and discharging measurement Internal resistance measurement: support, using the direct current two-wire method to test the internal resistance Charging function: support, full automatic cut off charging (does not support charging of lithium iron phosphate batteries) Discharge function: support, automatically stop when conditions are met, discharge current is not adjustable Automatic charging and discharging: support, automatic mode ends when the battery is fully charged Cycle charging and discharging: support, 1~9 cycles adjustable (only automatic mode support) Status prompt: support Heat dissipation mode: fan active heat dissipation Overheat protection: Support Stop discharge voltage: 2.5V, 2.6V, 2.7V, 2.8V, 2.9V, 3.0V, 3.1V, 3.2V, 3.3V, 3.4V, 3.5V, a total of 11 grades adjustable Discharge current: maximum about 1A current, not adjustable, does not support independent transformation Charging voltage: special battery charging chip control, maximum of about 1A charging, full charging voltage 4.2V Power failure save: only save the setting parameters, not save the measurement data Item size: 150 * 103 * 36mm / 5.91 * 4.06 * 1.42in Item weight: 200g / 7.05ounce Package size: 182 * 112 * 50mm / 7.07 * 4.41 * 1.97in Package weight: 260g / 9.17ounce Packing List: 1 * 18650 Battery Capacity Internal Resistance Tester 1 * Pry Bar