21V PCB Protection Board for BL1830 BL1840 BL1850 BL1860B LXT 400

21V Battery Charging PCB Protection Circuit Board – Compatible with BL1830, BL1840, BL1850 & BL1860B LXT 400

Keep your power tool batteries running safely and efficiently with this 21V Battery Charging PCB Protection Circuit Board. Designed as a direct-fit replacement for a range of popular LXT 400 lithium-ion battery packs, this board safeguards your battery cells against overcharge, over-discharge, and short-circuit conditions — helping extend battery life and maintain reliable performance.

Key Features

• Wide Compatibility: Fits 21V battery models BL1830, BL1840, BL1850, and BL1860B LXT 400 series.
• Battery Protection: Built-in circuitry guards against overcharging, over-discharging, and short circuits to keep your batteries safe during every charge cycle.
• Direct Replacement: Engineered as a drop-in replacement PCB, making battery repair and restoration straightforward for DIYers and technicians alike.
• Quality Construction: Made with reliable components for consistent electrical performance and durability under regular power tool use.
• Cost-Effective Repair: Restore a failing battery pack at a fraction of the cost of a full battery replacement.

Specifications

• Product Name: Mt21V Protection Board
• Voltage: 21V
• Compatible Models: BL1830, BL1840, BL1850, BL1860B (LXT 400 Series)
• Package Includes: 1 × Mt21V PCB Protection Circuit Board
• Country of Origin: Made in China

Important Notes

• Photos may not reflect actual size — please refer to the specifications above for dimensions.
• Minor measurement differences may occur due to manual measurement.
• Color may vary slightly depending on your monitor settings.
• Always disconnect the battery from any charger or tool before performing repairs or replacing internal components.

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• Looking for tools to help with your repair project? Browse our workshop essentials.

For general electrical safety guidance, visit the U.S. Consumer Product Safety Commission (CPSC) for tips on safely handling and repairing battery-powered devices.

Frequently Asked Questions

Q: Which battery models is this 21V PCB protection circuit board compatible with?

A: This circuit board is compatible with 21V lithium-ion battery packs including the BL1830, BL1840, BL1850, and BL1860B models in the LXT 400 series. Always verify your battery model number before purchasing to ensure a proper fit.

Q: What does the PCB protection circuit board do?

A: The PCB protection circuit board is responsible for monitoring and protecting the battery's cells during charging and discharging. It prevents overcharging, over-discharging, and short circuits — all of which can damage battery cells or create safety hazards during use.

Q: Is this a difficult repair to perform?

A: Replacing a PCB protection board requires basic electronics knowledge and soldering skills. If you are comfortable with battery disassembly and soldering, this is a straightforward repair. If you are unsure, we recommend consulting a qualified technician to ensure the repair is done safely and correctly.

Q: Will I receive exactly what is pictured?

A: Yes, you will receive one (1) Mt21V PCB Protection Circuit Board as described. Please note that due to differences in monitor calibration, the on-screen color may vary slightly from the actual product.