lithium battery capacity and internal resistance tester designed for 18650 batteries. The device is currently unavailable, but the page provides detailed information about its features.

1) Device Functionality

• Measures battery capacity (mAh) and internal resistance with good accuracy.
• Supports 4 independent channels for simultaneous charging, discharging, and testing.
• Uses a DC two‑wire method for more accurate resistance measurement when the battery is fully charged.
• Can perform automatic charge–discharge cycles up to 9 times.

2) Technical Specifications

• Operating voltage: 5V DC via dual Type‑C ports.
• Supported battery voltage range:
• Start charging: 2.8V
• Fully charged: 4.2V
• Stop discharge: adjustable between 2.5V and 3.5V (11 levels)
• Charge/discharge current: about 1A (not adjustable).
• Equipped with active fan cooling.
• Does not support LiFePO4 batteries.

3) Design & Usability

• Battery holder is designed for flat‑top 18650 cells; button‑top cells may fit tightly or not at all.
• Saves settings only, not measurement data, after power loss.
• Includes a plastic pry tool to remove tightly fitted batteries.

4) Customer Feedback

• Many users find it accurate and good value for the price.
• Common complaints:
• Tight battery holders.
• No included instructions.
• Requires two 2A USB power adapters to run all four channels at full speed.
• Some users reported receiving defective units that do not power on.

5) Box Contents

• Battery tester unit.
• Plastic pry bar tool.