Modular 18650 Battery Holder System | Expandable Battery Pack Spacer

Modular 18650 Battery Holder System

A modular battery holder system designed for rapid assembly of custom 18650 battery packs.

Features Single-cell modular holder design Expandable interlocking system Supports custom battery pack configurations Example 2S2P (4-cell) assembly included Suitable for robotics, ROV applications, drones, DIY power systems, and portable electronics Designed for standard 18650 cells (18 mm × 65 mm) Background

This design was originally created during the battery system development phase of a Vector Thrust ROV and was later expanded into a complete family of modular battery holders. Included Files Single-cell holder 2 × 2 battery holder assembly STEP files

A physical prototype was printed and verified for proper fit.

Print Testing

Printers Tested

Flashforge AD5X

Materials Tested

PLA PETG

Notes Designed around standard 18650 cell dimensions. The interlocking design allows expansion into larger battery pack configurations. Suitable for prototyping, battery storage, organization, and custom battery pack projects. Successfully printed and tested using both PLA and PETG materials. Printed examples are shown in the gallery images. Feedback

Suggestions, improvements, and project feedback are always appreciated.