LED flashlight with 18650 battery and USB-C connector, incl. TPU version!!!

*** NEW: Update to TPU version ***

Arguably the first flashlight with a full TPU housing on the market!

The 3D data is suitable for TPU, PLA and other materials.

Without screws, metal clips, etc.!

Absolutely unbreakable!

Ideal for the whole family!

Tired of having to constantly change the batteries of my old flashlight, due to the extreme brightness, I built myself one. It had to look nice, be sturdy, very bright, and the battery had to last a long time.

The result is now this flashlight, which I would like to share with you.

Because of the straightforward design, it is therefore also ideal as a gift. Printed in a beautiful color and packaged properly, it is a real eye-catcher! See pictures of the golden flashlight.

You can use an old existing lithium ion cell. Even with maybe 1000 mAh remaining capacity, you can run the flashlight for about 5-6 hours.

With a 3500mAh cell, the lighting time is up to 15 hours, and even up to 40 hours with a two-stage switch.

What makes this flashlight special is the simplicity of its construction. It consists of only 4 printed parts, a standard rocker switch, bright 5mm LEDs and charging electronics available everywhere. No LED driver is needed because when using white LEDs with a minimum required voltage of 2.9V, the LEDs lose brightness relatively late.

From the cell's maximum voltage of 4.2 V to 3.0 V, it lights up with high brightness. Only when the LEDs lose brightness, it is a sign that the flashlight should be charged. However, it can still be used until the LEDs then go out almost completely at 2.5V.

The integrated circuit prevents deep discharge of the built-in cell.

I would be very happy to see the flashlight as a "MAKE".

Have fun with it!

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Properties:

• Unique in design

• Very robust

• lies non-slip in the hand

• consists of only 4 printed parts

• very easy to assemble due to screwed elements

• only standard components are used

• very cheap, approx. 3 € without battery, approx. 6 € with battery

• Approx. 15 to 45 hours of lighting time (depending on battery and luminosity)

• 7 powerful LEDs connected in parallel (up to 1 watt, or more, depending on LED type).

• Is easy to operate

• Rechargeable via USB-C port in about 2-3 hours

• LED status indicator about charging status (charging / charging finished)

• Ready to use at any time for years with charged cell

• Deep discharge and overcharge protection

• Spare parts can be printed out yourself or purchased at low cost at any time

• In the TPU version absolutely unbreakable

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Components list:

4x 3D printed parts

7x 5mm LED (min. 20,000 mcd), 3V, e.g. 5mm LED white

1x Lithium-ion charging module with protection function and USB-C connector, e.g. USB-C charging module or here

1x lithium ion battery, 18650, typ. 3.7 V

1x Rocker switch, e.g. this

1x resistor 3.3 ohms, 0.5 W (for two-stage switch: 2.8 ohms and 9 ohms, 0.5W each)

3x cable, 14 cm, different colors

2x cable, 5 cm, different colors

1x piece of transparent filament (e.g. PETG) as light guide for the LED display (optional).

Optionally, a 2-stage switch can be installed with 2.8 Ohm (2x 5.6 in parallel) and 9 Ohm (2x 18 Ohm in parallel) resistance, for a two-stage LED flashlight. See pictures with red TPU flashlight.

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Files:

I found that the electronic board for charging and protecting the cell comes in two different board thicknesses. Therefore, I created two of the same case parts for different board thicknesses:

a) Electronics 1,5mm PCB.stl -> for 1,5mm thick PCB

b) Electronics 1mm PCB.stl -> for 1.0mm thick PCB

Other files:

body.stl -> main body, holds the cell and runs the cables

LED Holder.stl -> mounting plate for LEDs

Reflector.stl -> reflector to screw onto the main body

Flash Light Schematic.pdf -> Circuit diagram of the LED flashlight

Flash Light Assembly.pdf -> illustrated assembly instructions

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CAUTION: Do not shine in the eyes!

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Material: PLA, ABS, PETG and TPU

Support: only for electronics housing part and body

Filling: min. 50%

It is best to print the reflector in a light color, as it reflects better.

However, the effect of the reflector is negligible because the 5mm LEDs focus most of the light through their lens and send it forward. The proportion of reflected light is therefore relatively small.

Otherwise, there are no other requirements for the expression.

All prints in the pictures were made with an Ender 3 V2.