Project Hub /Robotics & Autonomous Systems/Self-Balancing/LED Emergency Light Cum Power Bank + Mini Fan Driver

Beginner

ANALOG / DISCRETE

₹500 – ₹1,500

3 – 6 Hours

Partial Kit

LED Emergency Light Cum Power Bank + Mini Fan Driver

A versatile DIY circuit that functions as an LED emergency light, a high-capacity power bank for mobile charging, and a USB OTG mini fan driver.

Originally published on ElectronicsForU

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
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
LM2596 Step Down DC-DC Buck Converter Rs. 99.00
2-Slot 18650 Holder with Protective Cover and On/Off Switch – Case Rs. 109.00
DC Motor Plastic Fan Blade Rs. 19.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
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: LED Strip / NeoPixel / WS2812
Microcontroller IC (DIP) / Chip
Enclosure / Box / Case
Four 3
Tiny 0.71cm
2.5V to 30V DC range mini digital voltmeter

Browse all components

How It Works

This versatile multi-function system operates around a central power storage bank consisting of four 3,000mAh Li-ion 18650 batteries wired in parallel to deliver a combined high-capacity 5V-compatible power source. Charging and recharging of the battery bank are managed by a 5V, 1A TP4056 micro USB charger module, which safely replenishes the cells while providing necessary overcharge and discharge protection. Power distribution from the battery pack is controlled by SPST switches that route current to specific output subsystems housed within a plastic switchboard enclosure. For emergency lighting, the circuit drives a 4V white LED mounted on an aluminum-sheet base for effective thermal dissipation. To provide portable device charging and run the OTG mini fan, an XL6009 DC-DC boost converter module steps up the nominal battery voltage to a stable 5V output distributed through integrated female USB sockets. Additionally, a tiny 0.71cm (0.28-inch) mini digital voltmeter with a 2.5V to 30V DC range is wired in conjunction with an SPDT switch, allowing the user to actively monitor the battery pack's real-time voltage levels. A transparent acrylic sheet covers and protects the front interface while maintaining visibility of the readout and internal layout.

Why Build This

Design a practical, high-capacity portable power bank and emergency lighting system using discrete modular components suitable for undergraduate engineering applications.

Integrate power conversion, battery management, and voltage monitoring circuits into a custom mechanical enclosure.

Implement portable DC power delivery capable of running auxiliary loads such as USB mini fans during power outages or field deployments.

Real-World Application

Portable emergency lighting during power outages, mobile phone charging during travel or emergencies, and powering portable DC mini fans.

Skills You'll Learn

DC-DC boost conversion

lithium-ion battery management

voltage monitoring integration

power distribution design

thermal management with aluminum substrates

enclosure assembly

Safety Precautions

Ensure correct polarity when wiring Li-ion cells in parallel and avoid overcharging by using proper modules with automatic cut-off.

Technology Tags

LI-ION BATTERY

TP4056 MODULE

XL6009 BOOST CONVERTER

DC-DC BOOSTER

LED LIGHTING

POWER BANK

USB OTG

VOLTMETER

Frequently Asked Questions

Why are four 18650 batteries wired in parallel instead of series?

Wiring them in parallel increases the total capacity (amperage-hours) while keeping the output voltage stable around the nominal 3.7V to 4.2V range, which is ideal for the TP4056 charger module and the XL6009 boost converter.

What is the purpose of the XL6009 module?

The XL6009 is a DC-DC boost converter that steps up the variable lower voltage from the Li-ion battery pack to a stable 5V output required for charging standard USB devices and running the OTG mini fan.

How does the mini digital voltmeter help during operation?

Connected via an SPDT switch, the voltmeter allows you to check the exact voltage of the battery pack in real-time, helping you determine when the system needs to be recharged via the TP4056 module.

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.

PRJ-00334