Build your own 3D-printed smart 18650 battery charger with real-time charging monitoring!
This project combines a custom 3D-printed enclosure, an ESP32-C3 SuperMini, an INA219 current sensor, a TP4056 charging module, and an OLED display to create a compact and practical battery charging station.
⚡ Features
- Real-time charging current monitoring in mA.
- Charging capacity tracking in mAh.
- Battery voltage measurement when not charging.
- Estimated battery percentage displayed on the OLED.
- Automatic battery detection with a “NO BATTERY” message.
- Automatic switching between charging and idle modes.
- Standalone operation without Wi-Fi or a computer.
🔧 Components
- ESP32-C3 SuperMini
- https://s.click.aliexpress.com/e/_c3TOjHOr
- https://s.click.aliexpress.com/e/_c38GxeoJ
- INA219 Current and Voltage Sensor
- https://s.click.aliexpress.com/e/_c4ShXJob
- https://s.click.aliexpress.com/e/_c39QjCzD
- https://s.click.aliexpress.com/e/_c3PuMCgr
- TP4056 USB-C Charging Module
- https://s.click.aliexpress.com/e/_c4kJ4L2P
- https://s.click.aliexpress.com/e/_c3bvh26L
- https://s.click.aliexpress.com/e/_c4McfTIn
- 0.96-inch OLED Display
- https://s.click.aliexpress.com/e/_c4Esig6x
- https://s.click.aliexpress.com/e/_c3PabbZ5
- https://s.click.aliexpress.com/e/_c3yfV0Fd
- MT3608 DC-DC Boost Converter
- https://s.click.aliexpress.com/e/_c4cTeCaL
- https://s.click.aliexpress.com/e/_c4qNFLYT
- https://s.click.aliexpress.com/e/_c3DMmxG
- AAA Battery Holder (3 Batteries)
https://s.click.aliexpress.com/e/_c4tnytV9 - https://s.click.aliexpress.com/e/_c4eKffar
- Reverse Polarity Protection Module
- https://s.click.aliexpress.com/e/_c4SrQcb9
- https://s.click.aliexpress.com/e/_c3j6iK6j
- https://s.click.aliexpress.com/e/_c3zs0DwX
- 18650 Battery Holder
- https://s.click.aliexpress.com/e/_c412Q1G7
- https://s.click.aliexpress.com/e/_c3wmiaYn
- M2 × 12 mm Nylon Screws
- https://s.click.aliexpress.com/e/_c3b6PHgx
- https://s.click.aliexpress.com/e/_c35IBvCL
- 22–24 AWG stranded wire
- https://s.click.aliexpress.com/e/_c2JB1xIf
- https://s.click.aliexpress.com/e/_c4aDxWQb
- 18650 Li-ion battery
- https://s.click.aliexpress.com/e/_c2JAESRN
- https://s.click.aliexpress.com/e/_c3MgXd1z
- https://s.click.aliexpress.com/e/_c3ZhQD0j
- Mini Rocker ON/OFF Switch
- https://s.click.aliexpress.com/e/_c3DC7Fgb
- https://s.click.aliexpress.com/e/_c3chRNtz
🖨️ 3D Printing
The enclosure is designed to accommodate the electronic components and provide a compact, organised charging station.
The design is suitable for PLA or PETG printing.
🔌 Wiring Diagram & Arduino Code
The complete wiring diagram is included in the project images to help you connect all the electronic components correctly.
The Arduino code is also available through the download link provided in the description.
🎥 Build Tutorial
A complete step-by-step tutorial, including assembly, wiring, programming, and testing, is available on my YouTube channel: Bambu3Design.
