Glow Bottle: a Cordless Stair Light Made From a Discarded Glass Bottle

I'm a student, and I live in a PG where the staircase is dark at night. There isn't enough light on it, and as a tenant I can't rewire the building. Every night I climbed those stairs slowly, feeling for the next step and hoping I wouldn't trip.

One day I looked at a discarded green glass bottle and saw something different. Someone had thrown it away, but the glass was still clear, strong and beautiful. It didn't look like trash. It looked like a lampshade waiting for a light.

So I gave it a second life. Inside the bottle I placed a spiral of LED filament. I 3D printed a small black housing, then added a rechargeable battery, a USB-C charging board and a switch. The lamp needs no wiring, no socket and no electrician. I fixed it to the stair wall, and now a soft green glow fills the stairwell. The light spirals up through the glass and spills across the wall tiles, so the lamp does more than help me see. It makes the staircase look better too. Climbing at night feels safer, and a little warmer, as if someone left a light on for me.

Because it's cordless, it works in more places than the stairs. I can carry it to my desk as a night lamp or place it on a shelf as an aesthetic decoration. (Optional: It runs for about X hours on one charge.)

Trash became light, and a dark corner of my student life became a little brighter and a lot more beautiful. If one thrown-away bottle can do this, so can the ones in your recycling bin. Here is how I built it.

For this project, I used a combination of recycled material, 3D-printed parts, electronics, and basic hardware.

♻️ Recycled Material

1. 1 × Used glass bottle — any discarded cold-drink, juice, or beverage glass bottle can be used.
2. The bottle becomes the main light diffuser and gives the project its distinctive appearance.
3. 3.7V 500mAh Battery - I recovered this rechargeable battery from an old, unused MP3 player instead of purchasing a new battery. It powers the lamp and gives another discarded electronic component a second life.

Lighting & Electronics

1. 1 × Flexible green 3.3V LED light — used as the light source inside the bottle.
2. 1 × TP4056 charging module — used for charging the rechargeable battery.
3. 1 × 3.7V 500mAh Li-ion/Li-Po battery — provides portable power.
4. 1 × Slide switch — used to turn the lamp ON/OFF.

️ 3D-Printed Parts

I designed and 3D-printed the lamp enclosure using an A1 Mini 3D printer.

1. Black filament — used for the main body/enclosure.
2. White filament — used for the lower/base section.
3. 1 × 3D printer — A1 Mini

Hardware

1. 8 × M2 × 4 mm screws
2. 2 × M2 bolts

Before building the lamp, I first thought about where a small, portable light could actually be useful.

I currently live in a PG where there are also older people. Some of them have reduced vision, especially in low-light conditions. Stairs can become difficult to see at night, increasing the possibility of trips or falls.

This made me think:

Can I create a small light that makes stairs and dark areas easier to see without needing a permanent electrical connection?

I wanted the solution to be:

1. 💡 Bright enough to provide useful low-level illumination
2. 🔋 Rechargeable, so it doesn't need to remain connected to a power source
3. 🎒 Portable, so it can be moved wherever extra light is needed
4. 💰 Low-cost, using easily available components
5. ♻️ Sustainable, by reusing discarded materials
6. 🪜 Suitable for stairways and other dark areas

This is where the idea for my rechargeable bottle stair light came from.

Instead of buying an expensive commercial night light, I decided to build one myself using a discarded glass bottle, a reclaimed battery from an old MP3 player, a small LED light, and a 3D-printed enclosure.

The Goal

The goal was not to create a high-powered room lamp. I wanted to create a small, low-cost, rechargeable light that can provide enough illumination to make a staircase or dark passage easier to navigate.

A simple light can make a dark staircase easier to see — and sometimes a small improvement in visibility can make a space feel much safer.

Why I chose a portable design

A permanently wired stair light isn't always practical, especially in a rented PG or temporary living space. A rechargeable design allows the lamp to be placed where it is needed without installing new wiring.

It can also be removed, recharged, and used in another location when required.

For the main body of the lamp, I selected a discarded green glass beverage bottle from the waste/recycling pile.

I chose this bottle because its green glass gives the lamp a natural colored glow when the LED is switched on. Its shape also works well as a light diffuser.

Cleaning the Bottle

Before using it, I thoroughly cleaned the bottle to remove any remaining dirt, dust, and residue.

1. I rinsed the bottle with water.
2. I washed the inside and outside using soap and water.
3. I removed any remaining labels or unwanted residue.
4. I rinsed it thoroughly with clean water.
5. Finally, I left the bottle to air-dry completely before starting the next step.

Tip: Make sure the bottle is completely dry before installing any electrical components around it.

The goal was to keep the bottle as close to its original form as possible while giving it a completely new purpose — from a discarded beverage container to the light diffuser of my rechargeable stair lamp.

After selecting the bottle, I designed the custom enclosure and mounting structure using Autodesk Fusion 360.

I wanted the design to have a simple, classic look inspired by traditional torches, while still feeling clean and modern. I was looking for a shape that would immediately communicate “light” without making the project look overly complicated.

The Minecraft torch was a great design inspiration for this. Its simple, recognizable form combines an old-fashioned torch-like appearance with a clean, modern visual style. I adapted that basic idea to fit my recycled bottle and the requirements of a wall-mounted lamp.

🧩 Designing Around the Electronics

While creating the model in Fusion 360, I also designed dedicated spaces for:

1. 🔋 3.7V 500mAh rechargeable battery
2. 🔌 TP4056 charging module
3. 💡 Flexible green LED
4. 🔘 Slide switch
5. 🧵 Connecting wires

The enclosure was designed around the actual components so that everything could fit neatly inside without unnecessary space or tangled wiring.

🎨 Design Philosophy

My aim was to combine three things:

Classic torch-inspired design + modern 3D printing + recycled material

I wanted the final lamp to look simple enough to feel familiar, but modern enough to fit into a contemporary room or stairway.

The Minecraft torch became the inspiration for the overall form because of its simple and recognizable torch-like design. I then adapted that idea into my own wall-mounted lamp using a discarded glass bottle and a custom 3D-printed enclosure.

Using Fusion 360 also allowed me to make the enclosure specifically for my bottle and electronics, making the final assembly cleaner, more compact, and easier to reproduce or modify.

After completing the designs in Autodesk Fusion 360, I 3D printed the custom parts using the Bambu Lab A1 Mini. The Base was printed in Natural White PLA, while the Bottle stand was printed in Pitch Black PLA.

Print Settings

1. 3D Printer: Bambu Lab A1 Mini
2. Filament: PLA
3. Moon Tray: Natural White PLA
4. Stand & Other Parts: Pitch Black PLA
5. Nozzle: 0.4 mm
6. Layer Height: 0.20 mm
7. Wall Loops: 3
8. Infill: 15%
9. Infill Pattern: Gyroid
10. Top Shell Layers: 5
11. Bottom Shell Layers: 5
12. Supports: Not required
13. Build Plate: Textured PEI Plate
14. Print Orientation: Flat side placed on the build plate where applicable
15. Bed Adhesion: Brim not required
16. Print Speed: Standard PLA profile
17. Nozzle Temperature: As set by the Bambu PLA profile
18. Bed Temperature: As set by the Bambu PLA profile
19. Slicing Software: Bambu Studio
20. Design Software: Autodesk Fusion 360

The printed parts were then checked for proper dimensions, fit, and assembly before moving on to the next stage of the project.

Before assembling the lamp, I first planned and understood how all the electronic components would be connected.

The main components are:

1. 3.7V 500mAh rechargeable battery — reclaimed from an old MP3 player
2. TP4056 charging module — for charging the battery
3. Slide switch — for turning the lamp ON/OFF
4. AUTABLES flexible green LED filament — used as the light source

🔧 Basic Connection

The overall connection is:

USB 5V → TP4056 → Battery → Slide Switch → Flexible LED

For the TP4056:

1. Battery + → B+
2. Battery − → B−
3. OUT+ → Slide Switch → LED +
4. OUT− → LED −

The TP4056 handles charging of the rechargeable battery, while the slide switch provides a simple ON/OFF control for the lamp.

💡 Checking the LED Polarity

One important thing I made sure to check was the polarity of the flexible LED filament.

Since I am using an AUTABLES flexible LED filament, I followed the manufacturer's instructions and checked which terminal/wire is positive (+) and which is negative (−) before making the connection.

Always check the polarity and electrical specifications of your particular LED according to the manufacturer's instructions before connecting it. Do not assume the polarity based only on the appearance of the wires.

⚠️ Important

The AUTABLES flexible filament I used is a low-voltage LED, so its required voltage and current should be checked before connecting it directly to a Li-ion battery. A 3.7V Li-ion battery can reach approximately 4.2V when fully charged, so the LED should be powered according to its specified requirements.

Before putting everything inside the 3D-printed enclosure, I tested the connections to make sure the battery, TP4056, switch, and LED were working correctly.

After completing the 3D printing and understanding the circuit, it was time to assemble all the components into their designed positions.

🔩 Assembly Process

1. Place all the components
2. I assembled the battery, TP4056 charging module, slide switch, and other components in their respective spaces inside the 3D-printed body, as shown in the 3D design.
3. Install the flexible LED
4. I carefully wrapped the green flexible LED filament around the black 3D-printed pole. The pole acts as the central support for the LED and helps keep the filament evenly positioned.
5. Insert the LED pole into the bottle
6. After wrapping the LED around the pole, I inserted the complete pole assembly into the recycled glass bottle. This places the LED inside the bottle and allows the green glass to diffuse the light.
7. Route the LED wires through the body
8. The positive (+) and negative (−) wires from the LED are routed through the designed openings in the 3D-printed body. The wires pass through the centre hole and the side hole, respectively, as shown in the design.
9. Connect the wires to the circuit
10. Once the wires were routed through the body, I connected them to the appropriate points in the circuit according to the connection described in Step 5.
11. Secure everything in place
12. Finally, I arranged and secured all the components in their designated positions and assembled the 3D-printed parts using the provided M2 screws and bolts.

This arrangement keeps the electronics organized inside the enclosure while the LED remains neatly positioned inside the recycled bottle.

Once the lamp was completely assembled, the next step was to install it on the wall.

📌 Mounting the Lamp

For this project, I used double-sided mounting tape to fix the lamp to the wall. This makes the installation simple and avoids drilling holes into the wall.

1. Choose the location
2. I selected a suitable location where the lamp could provide useful illumination, such as near a staircase, corridor, or other dark area.
3. Prepare the surface
4. I cleaned the wall surface to remove dust and dirt so that the adhesive could stick properly.
5. Apply the double-sided tape
6. I attached strips of strong double-sided mounting tape to the back of the 3D-printed enclosure.
7. Fix the lamp
8. I carefully positioned the lamp on the wall and pressed it firmly against the surface for a few seconds.
9. Check the mounting
10. Finally, I made sure the lamp was firmly attached and properly positioned before switching it on.

Note: You can use any suitable adhesive or mounting method depending on the wall surface and the weight of your lamp. For a heavier installation or a permanent mounting, screws or wall anchors may be more appropriate.

After fixing the lamp on the wall, I tested it in the actual environment to see how it looked and how well it worked.

When switched on at night, the green glass bottle produces a soft ambient glow, making the nearby stairs easier to see. This can be especially useful in areas where there is not enough light for comfortable movement at night.

✨ Testing Different Locations

I also tried placing the lamp in different areas to see how versatile it could be:

1. Beside the staircase — provides low-level illumination for the steps.
2. Beside a door — works as a small decorative and functional wall light.
3. In a hallway — provides ambient lighting in darker passages.
4. Other dark corners — can be moved and installed wherever additional low-level lighting is needed.

The recycled green bottle also gives the lamp a distinctive appearance, so it works not only as a practical light but also as a decorative piece.

The best part for me is that something that was originally going to be thrown away is now being used every night to make a dark area more visible. ♻️💚💡

The most important part of this project is not just the light itself. It is what the discarded materials become after the project is complete.

A bottle sitting in a dustbin has very little purpose in that moment. But with some creativity, design, and a few additional components, the same bottle can become a functional light that provides illumination, decoration, and practical value.

In other words:

The trash is now doing something that it could never do in the dustbin.

Instead of simply throwing the bottle away, I gave it a second life. Its value is no longer limited to being a discarded bottle — it has become a useful product.

💡 Where Can You Use It?

The concept can be adapted for many different places:

1. 🪜 Stairways — low-level lighting for better visibility at night.
2. 🚪 Beside doors — a small decorative entrance light.
3. 🏠 Hallways and corridors — ambient lighting for darker passages.
4. 🛏️ Bedrooms — soft night lighting.
5. 🌿 Balconies — decorative recycled lighting.
6. 🏕️ Camping or outdoor spaces — as a portable rechargeable light, with appropriate weather protection.
7. 📚 Study or reading areas — as an additional ambient light.
8. 🏪 Shops, cafés, or display areas — multiple bottles can be used to create a unique lighting installation.

🌈 Experiment With Different Bottles and Colours

This idea doesn't have to be limited to one green glass bottle.

You can experiment with:

Different LED colours

1. Green
2. Blue
3. Red
4. Warm white
5. Cool white
6. RGB LEDs

Different bottles and containers

1. Clear glass bottles
2. Green, blue, or brown glass bottles
3. Transparent plastic bottles
4. Reused food containers
5. Other discarded transparent or translucent packaging

Different combinations of bottle colour + LED colour can create completely different lighting effects.

🚀 The Idea Can Go Further

Instead of making just one lamp, several recycled bottles could be combined to create a wall lighting installation, with each bottle producing a different colour.

You could also improve the design with features such as:

1. Automatic light/dark sensing
2. Adjustable brightness
3. Motion detection
4. RGB colour changing
5. Solar charging
6. Magnetic mounting
7. Different 3D-printed enclosure designs
8. Modular designs for multiple bottles

The main idea is simple:

Don't just ask, "Where can I throw this away?" Ask, "What can I make it do?"

That change in perspective is what turns Trash into Treasure. ♻️💡