21700 Li-Ion Battery Case with PCB Protection Circuit Board

Keep your 21700 lithium-ion cells safely housed and electrically protected with this sturdy 21700 Li-Ion Battery Case with PCB Protection Circuit Board. Designed for hobbyists, electronics enthusiasts, and experienced battery pack builders, this enclosure combines a rugged plastic shell with a metal-reinforced frame and an integrated PCB protection circuit — all in one compact unit.

⚠ Important Notice: This product is a component only — no battery core is included. It is intended exclusively for individuals with hands-on experience in battery assembly and a solid understanding of lithium-ion cell performance and safety. Not recommended for beginners.

Key Features

• Integrated PCB Protection Circuit: Built-in circuit board helps guard against overcharge, over-discharge, and short-circuit conditions during battery pack assembly.
• Durable Construction: Made from high-quality plastic and metal for long-lasting everyday reliability.
• Compact & Practical Size: Measures 4.33 × 2.95 × 2.75 in (11 × 7.5 × 7 cm) — easy to work with and store.
• Sleek Black Finish: Clean, professional black colorway suits any workshop or electronics project setup.
• Designed for Battery Pack Repair & Assembly: Ideal for rebuilding or customizing 21700-format lithium-ion battery packs.
• Reusable & Rechargeable-Ready: Supports rechargeable battery configurations, reducing the need for single-use cells.

Product Specifications

Who Is This For?

This battery case is built for makers, electronics repair technicians, and experienced DIY battery pack assemblers. If you're rebuilding a power bank, building a custom e-bike battery, or repairing an existing lithium-ion pack using 21700 cells, this enclosure with its onboard protection circuit is a smart, reliable foundation for your project.

For more guidance on lithium-ion battery safety standards and handling, refer to the U.S. Consumer Product Safety Commission – Lithium-Ion Battery Safety Information Center.

Frequently Asked Questions

Q: What does the 21700 Li-Ion Battery Case with PCB Protection Circuit Board do?

A: This case provides a secure housing for 21700-format lithium-ion cells along with an integrated PCB protection circuit board designed to help protect against common electrical faults such as overcharging, over-discharging, and short circuits during battery pack assembly and use.

Q: Does this product include a battery?

A: No — this is a component-only product. The battery case and PCB protection circuit board are included, but the 21700 lithium-ion battery cell itself is not included. You will need to source compatible 21700 cells separately.

Q: Who should use this battery case?

A: This product is intended for individuals with practical experience in battery assembly and a solid understanding of lithium-ion cell performance and safety. It is suitable for electronics repair technicians, experienced hobbyists, and DIY battery pack builders — not recommended for beginners or those unfamiliar with lithium-ion battery handling.

Q: What are the dimensions and materials of this case?

A: The case measures 4.33 × 2.95 × 2.75 inches (11 × 7.5 × 7 cm) and is constructed from a combination of durable plastic and metal for strength and longevity.