The TP4056 is a compact charging IC designed for single-cell lithium-ion and lithium-polymer batteries. It controls charging through constant current and constant voltage, with automatic termination at 4.2 V. Modules often include USB input, LED indicators, and optional protection circuits. This article provides detailed information on specifications, charging process, wiring, safety, and applications.
Figure 1. TP4056 Module
TP4056 Module Overview
The TP4056 is a linear charging IC designed for single-cell lithium-ion and lithium-polymer batteries. It regulates voltage and current to ensure safe charging and automatically stops once the cell reaches 4.2 V. Commonly integrated into ready-made charging modules, it simplifies battery management by providing USB input (Micro-USB or Type-C), clear connection pads for 5 V input and battery terminals, and LED indicators for charging status. Some module versions also include built-in protection circuits to guard against overcharge, over-discharge, and short circuits.
TP4056 Electrical Specifications
| Parameter | Typical Value / Range |
|---|---|
| Input Voltage Range | 4.0 V – 8.0 V (maximum 8 V) |
| Charge Termination Voltage | 4.2 V ± 1.5% |
| Maximum Charge Current | Up to 1 A (set by resistor) |
| Trickle (Pte-Charge) Voltage | About 2.9 V |
| Termination Current | About 0.1 × I\_CHG (C/10) |
| Thermal Shutdown | \~145 °C (auto regulation) |
Components of the TP4056 Module
Each part of the module serves a specific role in controlling voltage, managing current, and protecting the battery.
TP4056 IC
The TP4056 IC is the core of the module, responsible for controlling the entire charging process. The chip automatically regulates voltage and current, stops charging when the battery is full, and restarts when the voltage drops.
Protection Circuitry (DW01A + 8205A MOSFETs)
Most TP4056 modules include a DW01A IC and dual 8205A MOSFETs that form a built-in battery management system (BMS). This section protects the battery from overcharging, over-discharging, short circuits, and excessive current. It automatically cuts off the load when voltage levels fall too low and reconnects once the battery is safe to use again. This ensures both user safety and battery durability.
Micro-USB or Type-C Input Port
The input port supplies the 5V DC power required for charging. It can connect to a USB charger, power bank, or computer. Most modules use a Micro-USB port, while newer versions include a Type-C connector for modern compatibility. The port connects to the IN+ (VCC) and IN– (GND) pins, providing stable power to the charging circuit.
Indicator LEDs
The module has two LEDs that show the charging status. The red LED turns on when the battery is charging, while the green or blue LED lights up once charging is complete or no battery is detected. These indicators, controlled by the TP4056’s internal pins, make it easy to monitor the process without external tools.
PROG Pin Resistor
A small resistor on the PROG pin determines the charging current. For example, a 1.2 kΩ resistor sets the current to about 1A, while 2 kΩ provides around 580 mA. Adjusting this resistor lets you control the charge speed based on battery size and safety requirements.
Capacitors
Two decoupling capacitors-one across the input and one across the battery terminals-help filter voltage noise and stabilize power flow. Typically between 1 µF and 10 µF, these capacitors ensure smooth charging and protect the circuit from sudden power fluctuations.
PCB and Copper Traces
All components are mounted on a printed circuit board (PCB) with copper traces that minimize resistance and help spread heat. Some versions include thermal vias for better heat dissipation during high-current charging, ensuring stable and long-term operation.
TP4056 Charging Process
Trickle Charge (~2.9 V or Lower)
When a battery is very low, the TP4056 begins with a small current. This stage is called trickle charge. It slowly raises the battery voltage to a safe level before normal charging begins. This prevents damage to batteries that are deeply discharged.
Constant Current (CC Mode)
Once the battery is recovered, the TP4056 provides a steady charging current. The exact value is set by the external PROG resistor, often 500 mA or 1 A. This stage is the fastest part of charging and restores most of the battery’s capacity.
Constant Voltage (CV Mode)
As the battery gets close to being full, the TP4056 switches to constant voltage mode. The voltage is held at 4.2 V while the charging current slowly decreases. This allows the battery to finish charging safely without going over the voltage limit.
Termination
Charging ends automatically when the current drops to about one-tenth of the programmed value. Stopping at this point helps reduce battery stress, avoids overheating, and improves the overall life of the battery.
TP4056 Module Variants
TP4056 Without Protection
| Feature | Details |
|---|---|
| Charging Control | Handles charging only, no safety features beyond the TP4056 IC itself. |
| Protection Circuits | Not included (no overcharge, over-discharge, or short-circuit safety). |
| Design | Smaller, simpler, and usually lower cost. |
| Best Use Case | Suitable when the battery already has its own BMS (Battery Management System) or when external protection is added. |
TP4056 With Protection
| Feature | Details |
|---|---|
| Charging Control | Same charging function as the basic TP4056. |
| Protection Circuits | Includes DW01A controller and FS8205A MOSFETs. Provides overcharge, over-discharge, and short-circuit protection. |
| Design | Slightly larger board, safer for general use. |
| Best Use Case | Ideal for beginners, DIY projects, and standalone cells (such as 18650 batteries without built-in protection). |
TP4056 Circuit Diagrams and Wiring
This image shows a TP4056 charging module circuit wired on a breadboard with a lithium-ion battery connected. The USB 5 V input provides the charging source, which enters through the module’s IN+ and IN– pins. The battery is connected to the OUT+ and OUT– terminals, where charging is managed by the TP4056 IC. The module also features LED indicators (STAT1/STAT2) that display the charging status, red for charging and blue/green for fully charged.
An NTC thermistor is included for temperature monitoring, ensuring safe charging by pausing the process if the battery overheats. The output terminals not only charge the cell but can also power an external load, as shown with the LED connected in the setup. This demonstrates the module’s ability to both charge the battery and supply power simultaneously.
TP4056 Common Issues and Fixes
| Issue | Description & Solution |
|---|---|
| LED Indicator Not Working | Check that the TP4056 module, battery, and power source are properly connected with correct polarity. Loose wiring or a damaged LED/resistor often causes failure. Replace any defective components and confirm solid solder joints. |
| Charging Slowly | Slow charging usually results from low input current or voltage drops. Use a stable 5 V / 1 A (or higher) power source, a short quality USB cable, and ensure the PROG resistor sets the correct current. Avoid thin or corroded connectors. |
| Overheating | The TP4056 may warm slightly, but excess heat signals poor airflow or high current. Keep the board ventilated and reduce current by increasing the PROG resistor value. Continuous overheating can shorten component life. |
| Charging Interruptions | Unstable power or loose terminals often stop charging unexpectedly. Use a reliable DC adapter instead of computer USB power, and ensure all wires and terminals are tightly secured. |
| Battery Not Holding Charge | Batteries that discharge quickly may be aged or low quality. Always use genuine lithium-ion or lithium-polymer cells and avoid deep discharges below 3 V. Replace degraded batteries for reliable capacity. |
| Module Not Starting | If charging doesn’t start, confirm the input voltage is 4.5 V–5.5 V. Damaged USB ports, poor soldering, or a faulty TP4056 IC may be responsible. Inspect connections and replace the module if necessary. |
| Battery Overcharging | A battery exceeding 4.2 V indicates a defective IC or wrong voltage reference. Stop charging immediately and replace the module. Always check output voltage with a multimeter before reuse. |
| Both LEDs ON or Flickering | When both “charging” and “full” LEDs light or flicker, the issue is unstable input or bad solder joints. Re-solder weak connections and use a steady 5 V power source for consistent operation. |
| Module Not Detecting Battery | Deeply discharged cells below 2.5 V may not be detected. Pre-charge the battery gently at 4.2 V / < 100 mA until voltage exceeds 3 V, then reconnect it for normal charging. |
| Short Circuit or Smoke | Smoke or heating suggests reversed polarity or wiring mistakes. Double-check all connections before powering on. Use modules with DW01A and 8205A MOSFETs for built-in protection against shorts and overcurrent. |
TP4056 Applications
• Portable Electronics: Powers rechargeable gadgets such as cameras, MP3 players, and handheld tools.
• DIY Battery Packs: Ideal for custom battery assemblies in small devices and robotics.
• Battery Management Systems: Handles charging control in lithium-based battery setups.
• Power Banks: Used in portable chargers for recharging phones and small devices.
• Solar Chargers: Works with solar panels for renewable, portable power systems.
• Arduino and IoT Projects: Provides regulated charging for microcontroller-based trackers, sensors, and data loggers.
• Emergency Power Supplies: Keeps essential devices running during power outages.
• Audio and Lighting Devices: Powers rechargeable speakers, amplifiers, flashlights, and lamps.
• Wearable and Smart Devices: Used in low-power gadgets like fitness bands and smart locks.
• Educational Kits: Common in learning projects for beginners due to its simple USB charging and LED indicators.
Conclusion
The TP4056 module offers safe and efficient charging for lithium batteries. With features like adjustable charge current, status indicators, and optional protection, it is well-suited for many battery-powered projects. Proper use of resistors, wiring, and temperature monitoring ensures reliable performance and longer battery life, making the TP4056 a trusted choice for compact charging solutions.
Frequently Asked Questions
Q1. Can the TP4056 charge multiple batteries?
No. It only charges one cell. Use a BMS for multi-cell packs.
Q2. What is the standby current of the TP4056?
Very low, usually a few microamps.
Q3. Does the TP4056 support fast charging like QC or PD?
No. It only works with a fixed 5 V supply.
Q4. Does the TP4056 generate heat while charging?
Yes. It dissipates extra voltage as heat, more noticeable at high current.
Q5. Can the TP4056 run directly from solar panels?
Not reliably. Use a regulator for a stable 5 V input.
Q6. What battery size can the TP4056 charge?
Any capacity, as long as the charge current is set correctly with the PROG resistor.