21700 Battery Storage Case | Compatible with 18650 / Button Top / Protection Board / Mixed Storage / All-Printed

For more storage, desk setup, and office supplies, please follow this collection (click to jump): https://makerworld.com/en/collections/4264605

Button top / With protection board / 2-12 cell capacity / Oversized batteries / 21700 and 18650 mixed storage

All your needs can be met here (if you have additional requests, please comment directly, the author will respond quickly!)

Battery Storage Box Series (Click image to jump)
21700 Battery Box	18650 Battery Box	AA/AAA Battery Box
Button top / with protection board / 18650 compatible 2-12 cell capacity / supports mixed storage	Button top / with protection board 2-12 cell capacity	2-24 cell capacity / mixed storage

For the highest print quality, please print the box and lid on separate plates to avoid cooling lines

🔋21700 Battery Box｜Ultimate Edition

📖Preface

Recently, I've become obsessed with flashlights and bought many 21700 batteries. I realized it's quite dangerous to carry them around without a suitable box when going out (due to potential compression and short-circuit risks if bare terminals touch conductive metal). So, I planned to print two boxes for my own use, but still encountered various problems with existing designs. Therefore, I redesigned one myself and made it open source. The main issues with battery boxes currently on the market are:

1. 📏 Insufficient Diameter Clearance: While a 22mm diameter can fit most 21700 batteries, some still don't fit due to reasons such as: secondary heat shrink wrapping (modified button top), brand-specific thickening, or users not calibrating filament shrinkage
2. 📐 Insufficient Height Compatibility: Many battery boxes are designed only for original 70mm flat-top batteries, meaning 73mm small button-top, 74mm large button-top, and 75mm protected batteries do not fit
3. 🧽 No Internal Cushioning: Batteries can easily rattle inside the box, potentially leading to outer wrapper damage over time
4. 🧩 Not an All-Printed Design: Requires purchasing hardware such as screws and hinges, making it less flexible for printing and use
5. 🖨️ Not Optimized for 3D Printing: Many models are not specifically optimized for FDM 3D printing characteristics, making them not simple enough to print
6. 🔄 Insufficient Flexibility in Use: Cannot meet special needs such as mixed storage of 18650 and 21700 batteries

✨Design Highlights

1. 📐 Excellent Size Compatibility: Compatible with batteries up to 22.5mm in diameter and 76mm in height (covering almost 100% of 21700 batteries)
2. 🔢 Multiple Capacity Options: Available in 2-12 cell capacities
3. 🖨️ 3D Print Optimization: No supports, no hardware, easy assembly
4. 📏 Includes Cushioning Pad Template: Easy to cut suitable cushioning foam, protecting batteries
5. 🧩 Flexible Usage Design: Additional adapter modules are included to meet special needs such as mixed storage of 18650 and 21700 batteries, and batteries with slight size variations

🎨Offers three versions: dual-color (with text), single-color (with text), and single-color (without text)

📘Instructions for Use

1. If there are special usage requirements, you can print size adapter shims. For 18650 adapters: height reduced by 5mm, diameter reduced by 3mm. Each circular shim adds 1mm to the height

2. It is recommended to purchase PU self-adhesive foam to stick inside the lid, with dimensions of 25mm wide * 5mm thick. Actual tests show that 8mm thick can also close; if you prefer a very snug fit, you can choose 8mm

   ⚠️ Do not purchase EVA foam, pearl cotton, etc. Foam that is too hard may damage the lid hinge. You must buy PU (polyurethane) foam!

   ⬇️🛒Click image to jump to purchase link🛒⬇️

   

3. Size versions are backward compatible; for example, the 76mm version is compatible with all batteries shorter than 76mm. However, a too-large gap can cause excessive rattling, so it's recommended to choose the most suitable version based on your existing batteries or print shims to increase height for installation

🛠️Installation Diagram