2pcs 3S 12.6V BMS Li-ion Battery Protection Board for Drills

ZUIDID 3S 12.6V 6A BMS Li-ion Battery Protection Board — 2-Pack

Keep your 18650 lithium battery packs running safely and efficiently with this 2-pack of ZUIDID 3S 12.6V BMS (Battery Management System) Protection Boards. Designed for 3-cell series lithium-ion configurations, these compact PCB boards guard against overcharge, over-discharge, overcurrent, and short-circuit events — making them an ideal upgrade or replacement for cordless drills, rotary tools, electric angle grinders, and other 12V handheld power equipment.

With CE certification and a wide operating temperature range of -40°C to +85°C, these boards deliver reliable performance in both workshop and field conditions. At just 33.7 × 36.5 mm, they fit neatly inside standard 18650 battery holders without adding bulk.

Made in Mainland China.

Key Features

• 4-in-1 Protection: Overcharge, over-discharge, overcurrent, and short-circuit protection in a single board
• Balanced Charging: Enhances cell balance for longer pack lifespan
• 3S Configuration: Supports 3 lithium-ion cells in series (12.6V nominal pack)
• CE Certified: Meets European conformity standards
• Wide Temperature Range: Operates from -40°C to +85°C
• Compact Form Factor: 33.7 × 36.5 mm — fits standard 18650 holders
• Value Pack: 2 boards included per order

Technical Specifications

Compatible Applications

• Cordless / handheld lithium drills
• Rotary tools and accessories
• Electric angle grinders
• DIY 18650 battery pack builds
• 12V DC electrical tool power systems

What's in the Box

• 2 × 3S 12.6V 6A BMS Li-ion Battery Protection Board

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Note: Manual measurement may result in a 1–2 mm variance. Colors in product images may differ slightly from the actual item due to monitor calibration differences.

Learn more: ENERGY STAR product efficiency guidance

Frequently Asked Questions

Q: What does a 3S BMS protection board do for my lithium battery pack?

A: A 3S BMS (Battery Management System) protection board monitors and manages three lithium-ion cells connected in series. It actively prevents overcharging (above 4.25V per cell), over-discharging (below 2.5V per cell), overcurrent draw, and short-circuit events — all of which can damage cells or create safety hazards. This ZUIDID board adds all four protections plus cell-balancing functionality to your 12.6V 18650 battery pack.

Q: Is this BMS board compatible with standard 18650 lithium-ion cells?

A: Yes. This board is specifically designed for 3-cell series (3S) configurations using standard 18650 Li-ion cells. It supports a charging voltage of 12.6V–13V and is commonly used in DIY battery packs for cordless drills, rotary tools, and other 12V DC power tools.

Q: What is the maximum current this protection board can handle?

A: The board supports a maximum operating current of 8A continuously, a static working current of 5–15A, and a transient peak current of 40A ± 5A. The overcurrent protection kicks in at 26A ± 2A, and the short-circuit protection triggers within 300 microseconds, keeping your battery pack and connected tools safe.

Q: How many boards do I receive in one order?

A: Each order includes 2 BMS protection boards, giving you a spare on hand or enough to build two separate battery packs.

Production & Packaging Notice

To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.