Project Hub /Basic Analog & Power Electronics/Battery Chargers & Charging Circuits/Build Your Own Power Bank

Beginner

ANALOG / DISCRETE

₹500 – ₹1,500

3 – 6 Hours

Partial Kit

Build Your Own Power Bank

Learn how to build a 4500mAh portable power bank using three 18650 lithium-ion batteries, a power bank charging module, and a 3D printed enclosure.

Originally published on CircuitDigest

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

1200mAh 18650 Li-ion Bat – Reliable 3.7V Power Cell Rs. 129.00
Cable for Arduino Nano (USB 2.0 A to USB 2.0 Mini B) 30cm Rs. 69.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

We don't carry yet: Battery (generic / unspecified)
Enclosure / Box / Case

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How It Works

This portable power bank project operates by combining three 18650 lithium-ion cells in a parallel configuration to deliver a cumulative capacity of 4500mAh at a nominal voltage of 3.7 volts. The dedicated power bank module acts as the core power management and regulation hub for the system. Using the included Micro USB cable, external power is supplied to the module, which safely regulates the charging current and voltage applied to the lithium-ion battery pack. During discharge, the module steps up the 3.7V nominal output from the parallel cells to a steady 5V DC output suitable for standard USB-powered devices. The entire electrical assembly is safely housed inside a custom-designed 3D printed enclosure modeled using Fusion 360, ensuring proper mechanical fit and physical protection for the internal wiring and discrete components.

Why Build This

Design and prototype custom power supply enclosures tailored to specific hardware dimensions using CAD software.

Understand practical power management, voltage step-up conversion, and lithium-ion battery integration for portable engineering prototypes.

Fabricate a reliable, high-capacity 4500mAh mobile charging solution for field testing USB-powered development boards and microcontrollers.

Real-World Application

Portable charging solutions for mobile phones and USB-powered devices when wall chargers are unavailable.

Skills You'll Learn

Lithium-ion battery pack assembly

power management module integration

DC-DC voltage boost conversion

CAD enclosure modeling

basic circuit wiring and polarity verification

Safety Precautions

Handle lithium-ion batteries with care. Ensure correct polarity when wiring the battery pack to the power bank module to prevent short circuits and potential thermal runaway.

Technology Tags

18650 BATTERY

LITHIUM-ION

TP4056

POWER BANK

BOOST CONVERTER

3D PRINTING

FUSION 360

Frequently Asked Questions

Why are the three 18650 batteries wired in parallel instead of series?

Wiring them in parallel keeps the overall voltage at a nominal 3.7V while tripling the total capacity to 4500mAh, which matches the input requirements of the standard power bank module.

Can I use different types or capacities of 18650 cells?

It is strongly recommended to use identical cells with the same capacity and chemistry to prevent uneven charging and discharging, which can cause performance issues or safety hazards.

What is the purpose of Fusion 360 in this electronics project?

Fusion 360 is used to design and 3D print a custom physical enclosure that securely holds the battery pack and power bank module together in a portable form factor.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

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