Charger
Using TP4056 Charger with Espressif ESP32
What is the TP4056?
TP4056 practical reference
The standard single-cell lithium charging module, often bundled with over-charge/discharge protection circuitry on the same board. Built around the TP4056 linear charger IC (commonly paired with a DW01 protection chip and dual MOSFETs), it takes a 5V USB input and safely charges a single-cell Li-ion/LiPo battery with the correct constant-current/constant-voltage profile, while the protection circuitry cuts off the battery if it's charged too high, discharged too low, or short-circuited — making it the near-universal choice for any DIY project that charges its own lithium battery from USB.
Key specifications
- Chipset: TP4056 linear Li-ion/LiPo charger IC, commonly paired with a DW01A protection IC and dual MOSFETs on the same board
- Input voltage: 4.5V–5.5V DC, typically via Micro-USB or USB-C connector
- Charge voltage: 4.2V constant-voltage regulation for standard single-cell Li-ion/LiPo
- Charge current: Adjustable via an onboard resistor (commonly set to ~1A by default, some boards include a resistor pad to change it)
- Charge algorithm: Constant-current / constant-voltage (CC/CV) with automatic trickle charge for deeply discharged cells and charge termination near full
- Protection features (on modules with DW01): Over-charge protection, over-discharge protection, over-current/short-circuit protection
- Status indication: Onboard LEDs typically indicate charging (red) and fully charged (blue/green), color scheme varies by board
- Interface: Passive power circuit — USB in, battery and load out, no digital interface required
Pinout and connection notes
Always verify whether your specific TP4056 board includes the DW01 protection chip (look for two extra small MOSFETs and a small SOT23-6 IC near the battery terminals) — bare TP4056-only boards without protection should never be used to directly power a load while charging, since an over-discharged or over-charged unprotected cell is a real fire risk. Boards with protection expose separate B+/B- (battery) and OUT+/OUT- (load) pads so the load can draw power safely even during charging.
- IN+ (USB VBUS): 5V input from USB, via Micro-USB or USB-C connector
- IN- (GND): USB ground
- B+ (Battery+): Connect to the positive terminal of the single-cell Li-ion/LiPo battery
- B- (Battery-): Connect to the negative terminal of the battery
- OUT+: Positive output to the project load, present on boards with a protection circuit and separate load output
- OUT-: Negative output to the project load
Integration checklist
- Confirm the exact part number and breakout-board revision.
- Verify supply voltage, current demand, logic levels, and signal direction against the datasheet.
- Check controller pin assignments and bus address or interface mode against the example code.
- Power up with external loads disconnected, then test signals before full integration.
- If readings or communication fail, check power and ground first, then pin mapping, interface settings, and library initialization.
Troubleshooting and reproducibility
Record the board used, wiring, library/version, supply arrangement, and measured behavior. Use the selected board-specific wiring example as the source of truth. Never assume visually similar modules share identical voltage tolerance or pin order.
Setting Up TP4056 with Espressif ESP32
Wiring
| Component pin | Espressif ESP32 pin | Note |
|---|---|---|
| IN+ / IN- | USB / power adapter | Charging input — not connected to the ESP32 |
| B+ / B- | — | To the single-cell Li-ion/LiPo battery |
| OUT+ | 5V / VIN pin (ideally via a boost converter) | Never wire raw battery voltage to the 3V3 pin — a freshly charged cell at 4.2V exceeds the ESP32's absolute max there. Feed 5V/VIN and let the board's onboard regulator step it down. |
| OUT- | GND |
Swipe sideways to see every column →
- This is the single most common mistake with this combo: raw Li-ion voltage (up to 4.2V) exceeds the ESP32's absolute maximum on 3V3 — always route through 5V/VIN with onboard regulation, or a dedicated battery-ready dev board, never straight to 3V3.
- Same LED-vs-actual-charge caveat as the other boards: the LED shows charging status, not remaining capacity.
- ADC_11db attenuation is needed here just to read up near 3.3V at all — the ESP32 ADC's default range is more limited.
Related Components
18650 Holder
Single-cell 18650 holder for portable project power.
AMS1117 33
Fixed 3.3V linear regulator for powering logic-level components.
LM2596
Adjustable buck converter for efficiently stepping down higher voltages to project logic levels.
MT3608
Adjustable step-up converter for boosting low battery voltages to component requirements.
Related Guides & Projects
MicroPython vs Arduino on ESP32: Which Should You Learn First?
An honest comparison for beginners: where MicroPython is easier, where Arduino C++ is faster, how libraries and memory differ, and how to choose based on your project instead of hype.
MicroPython ESP32 Web Server: Control an LED or Relay from Your Browser
Create a working web server with the socket module, parse requests, serve a responsive control page for an LED or a relay, keep the displayed state truthful, choose a safe relay startup state and make the server survive bad or repeated requests.
MicroPython on ESP32 and Raspberry Pi Pico W: The Complete Guide
A structured MicroPython learning path for ESP32 and Pico W. Set up your tools, control GPIO, read sensors, connect to WiFi, build web servers, publish MQTT data and make projects reliable. Start here, then follow the links by level.
boot.py vs main.py in MicroPython: What Runs, When and Why
Understand the difference between boot.py and main.py in MicroPython, startup order, Wi-Fi setup, project structure, and recovery from boot errors.