Feature Highlights: 1. Charging Protection Circuit Board (No Battery Core) – Designed for repairing and assembling battery packs. Suitable only for users familiar with battery performance and hands-on battery assembly experience. 2. Smart Protection & Monitoring – Built-in IC detects cell voltage and current, and records usage cycles. Provides full protection: overheat, overvoltage, undervoltage, overcurrent, and overcharge protection. 3. Low Voltage Cutoff – All series support low-voltage shutdown to help extend battery life and ensure safety. 4. Wide Compatibility & Durability – Works with many power tool brands. Stable quality, anti-vibration design, ideal for use with torque wrenches, impact drills, angle grinders, and more. 5. Reliable & Updated Design – PCB color and version may vary based on latest inventory. Design may be updated due to supply chain or production improvements. Product Details: This circuit board is used for charging protection in lithium battery packs. It does not include the battery itself. Built with precision components to monitor voltage, current, and usage history while offering multiple safety protections. Easy to install for experienced users, it ensures stable performance even in high-vibration tools. Compatible with 20V Li-Ion battery systems and commonly used in power tool maintenance and DIY battery assembly. Specifications: - Color: Blue, White, Green, Red, or Green PCB (color and version subject to current inventory) - Material: Metal + Plastic - Package Includes: 3 sets of lithium battery charging protection circuit boards (batteries not included) Note: Slight color differences may occur due to lighting and screen settings. Measurements may have an error margin of +/- 1–3 cm.