Makita 21V 5-Cell Battery Protection Board with Balanced Charging & Temperature Control

Keep your Makita 21V battery pack running safely and efficiently with this purpose-built 5-string (5S) Battery Management System (BMS) protection board. Featuring a 5Mos3 alloy MOSFET configuration, this board delivers reliable balanced cell protection, over-charge and over-discharge cutoff, short-circuit protection, and integrated temperature control — all in a compact, lightweight 30g bagged unit.

Whether you're rebuilding a worn-out Makita battery pack or upgrading an existing one, this protection board is a cost-effective solution that helps extend the life of your cells and safeguard your tools.

Key Features

Compatible with: Makita 21V 5-string (5S) battery configurations
MOSFET Type: 5Mos3 alloy for reliable switching performance
Balanced Cell Protection: Keeps all 5 cells balanced for maximum capacity and lifespan
Temperature Control: Built-in thermal management helps prevent overheating
Over-charge / Over-discharge Protection: Automatic cutoff to protect your cells
Short-Circuit Protection: Instant response to prevent damage
CE Certified: Meets European safety and quality standards
Lightweight: Only 30g per unit
Packing: Individually bagged for safe shipping and storage

Specifications

Voltage	21V (5S Li-ion)
MOSFET	5Mos3 Alloy
Weight	30g
Certification	CE
Battery Included	No
Charger Included	No
Country of Origin	Made in Mainland China

What's in the Box?

1 × Makita 21V 5-String 5Mos3 BMS Balanced Protection Board

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For more information on battery safety and best practices for lithium-ion battery use, visit the U.S. Consumer Product Safety Commission – Lithium-Ion Battery Safety.

Learn more: Battery management system

Frequently Asked Questions

Q: What battery packs is this Makita 21V BMS protection board compatible with?

A: This protection board is specifically designed for Makita 21V 5-string (5S) lithium-ion battery packs using the 5Mos3 alloy MOSFET configuration. Always verify your cell count and voltage before installing to ensure compatibility.

Q: Does the board include balanced charging protection for all 5 cells?

A: Yes! The board includes a built-in cell balancing function that actively keeps all 5 cells at equal charge levels during charging and discharging, which significantly extends overall battery lifespan and maintains consistent performance.

Q: Is a battery or charger included with this BMS board?

A: No — this listing is for the protection board only. No battery cells or charger are included. It is intended as a replacement or upgrade component for DIY battery pack repairs or rebuilds.

Q: What does the temperature control feature do?

A: The integrated temperature control monitors the heat generated by the battery cells and MOSFET components during operation. If temperatures rise to unsafe levels, the board can automatically cut power to prevent overheating, cell damage, or potential safety hazards.

Made with care

Great value

Elegant design

Quality materials

This product is crafted with quality materials to ensure durability and performance. Designed with your convenience in mind, it seamlessly fits into your everyday life.

We strive to process and ship all orders in a timely manner, working diligently to ensure that your items are on their way to you as soon as possible.

We are committed to ensuring a positive shopping experience for all our customers. If for any reason you wish to return an item, we invite you to reach out to our team for assistance, and we will evaluate every return request with care and consideration.