15x21700 Li-Ion Battery Case & PCB Protection Board for Milwaukee 18V

Build Your Own Milwaukee 18V 12Ah Li-Ion Battery Pack

Take your power tool projects to the next level with this DIY battery pack housing kit. Designed for compatibility with Milwaukee 18V platforms, this plastic case and PCB charging protection circuit board set provides everything you need to assemble a custom 18V 12Ah Li-Ion battery pack using 15 pieces of 21700-format lithium-ion cells (not included). Perfect for makers, DIY enthusiasts, and electronics hobbyists who want to save money rebuilding or upgrading their power tool batteries.

⚠️ Important Notice: This product is a semi-manufactured component kit intended for experienced DIY builders. Assembly requires professional knowledge and proper tools including a spot welding machine, soldering iron, and multimeter. Battery cells are NOT included — you must source 15x 21700 Li-Ion cells separately. Always follow all lithium-ion battery safety guidelines during assembly.

Made in Mainland China.

Key Features

• ✅ Compatible Housing: Designed to fit Milwaukee M18 18V battery platform configurations
• ✅ PCB Charging Protection: Built-in protection circuit board helps guard against overcharge, over-discharge, and short circuit
• ✅ Supports 15x 21700 Cells: Accommodates a 15-cell configuration for a high-capacity 12Ah pack
• ✅ Durable Plastic Shell: Sturdy plastic housing engineered to house and protect your cell assembly
• ✅ 100% Brand New: Fresh stock — never used or refurbished
• ✅ Customizable Build: Semi-manufactured design allows you to tailor the pack to your specific power needs
• ✅ DIY-Friendly Design: Designed for hobbyists and professionals comfortable with battery pack assembly

Specifications

What's in the Box?

• 1x M18 Li-Ion Battery Plastic Case with PCB Charging Protection Circuit Board Kit

Note: Battery cells, charger, and spot welding equipment are NOT included. Images are for reference only — actual color and size may vary slightly. Measurement tolerance: ±1–3cm.

Tools Required for Assembly

• Spot Welding Machine
• Soldering Iron
• Multimeter
• 15x 21700 Li-Ion Battery Cells (sourced separately)

Safety Information

Lithium-ion batteries can be hazardous if mishandled. Always follow proper safety protocols during assembly and use. For guidance on lithium battery safety, refer to the U.S. Occupational Safety & Health Administration or review battery handling best practices from CDC NIOSH on Lithium Battery Safety.

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Frequently Asked Questions

Q: Are the 21700 lithium-ion battery cells included with this kit?

A: No, the 21700 Li-Ion battery cells are not included. This kit contains only the plastic housing case and the PCB charging protection circuit board. You will need to source 15 pieces of 21700-format Li-Ion cells separately to complete your battery pack build.

Q: Is this kit compatible with all Milwaukee M18 tools?

A: This case and PCB kit is designed to be compatible with the Milwaukee M18 18V battery platform configuration. However, as this is a DIY semi-manufactured kit, final performance and compatibility will depend on the quality of your assembly and the 21700 cells you choose. We recommend verifying compatibility before beginning assembly.

Q: What tools do I need to assemble this battery pack?

A: To safely assemble this battery pack, you will need a spot welding machine (for connecting cell terminals), a soldering iron (for PCB connections), and a multimeter (to verify voltages and connections). Prior experience with Li-Ion battery assembly is strongly recommended.

Q: What does the PCB charging protection circuit board do?

A: The PCB (Protection Circuit Board) is a critical safety component in lithium-ion battery packs. It helps protect the battery cells against overcharging, over-discharging, overcurrent, and short circuits — all of which can damage cells or create safety hazards. This board is included in the kit and is pre-fitted to the housing.

Q: Is this product suitable for beginners?

A: This product is intended for individuals with professional knowledge and hands-on experience in battery assembly. It is not recommended for beginners without prior experience working with lithium-ion cells and electronics assembly tools. Improper assembly can pose serious safety risks.