Lithium Ion Battery Charger Module : Design Guide

Lithium-ion batteries have revolutionized the world of portable electronics, providing high energy density, lightweight, and long cycle life. To maximize the efficiency and lifespan of these batteries, it is crucial to use a reliable and effective charging module. The Lithium-Ion Battery Charger Module is designed specifically for this purpose, offering a range of features that ensure safe and efficient charging of lithium-ion cells.

What is a Battery Management System (BMS)?

A Battery Management System (BMS) is a crucial electronic circuit designed to protect and manage rechargeable cells or battery packs. It ensures the safe and efficient operation of batteries by performing several key functions:

Key Functions of a BMS:

1. Overcharge Protection: Prevents the battery from being charged beyond its maximum voltage limit, which can cause overheating, degradation, or even explosion.
2. Overdischarge Protection: Stops the battery from discharging below its minimum voltage limit, which can lead to capacity loss or battery damage.
3. Short Circuit Protection: Prevents short circuits that can cause severe damage or pose safety hazards.
4. Voltage Monitoring: Continuously monitors the voltage of individual cells and the overall battery pack to ensure balanced charging and discharging.
5. Current Monitoring: Tracks the current flow into and out of the battery to prevent overcurrent conditions that can damage the cells.
6. Temperature Monitoring: Monitors the battery temperature to prevent overheating and ensure safe operating conditions.

By maintaining these parameters within optimal ranges, a BMS helps to extend the life of the battery, improve its performance, and ensure safe operation.

TP4056: Single Lithium Ion Battery Charger Module

The TP4056 is a popular charger module used for managing single lithium-ion cells. It integrates a battery management system tailored for individual lithium-ion cells, providing a reliable and efficient solution for charging and protecting the battery.

Features of TP4056 Module:

1. Linear Charging: Uses a linear charging method to ensure stable and efficient charging of the lithium-ion cell.
2. Overcharge Protection: Automatically stops charging once the battery reaches its full charge voltage.
3. Trickle Charging: Applies a small current to a deeply discharged battery to safely bring it up to a level where regular charging can occur.
4. Current Regulation: Controls the charging current to prevent overcurrent conditions.
5. LED Indicators: Includes LED indicators to show the charging status (charging, fully charged).

The TP4056 module is widely used in DIY projects, portable electronics, and other applications where single-cell lithium-ion batteries are employed. Its integrated protection features and ease of use make it a reliable choice for battery management in various devices.

Pinouts of TP40546 Lithium Ion Battery Charger Module

Lithium Ion Battery Charger Module Single Cell 3.7V Charging Module: Basic Features & Parameters

Input and Output Specifications:

• Input Supply Voltage: 4.5V – 6.0V
• Input Supply Current: 1.5A
• Constant Charging Voltage: 4.2V
• Full Charge Cut-off Voltage: 4.2V ±1.5%
• Constant Charging Current: Adjustable from 130mA to 1A max with a reprogrammable resistor (R3 = 1.2kΩ for 1000mA)
• Max Power: 4.2W

Indicators:

• Charging Indicator LED: Red
• Full Charging Indicator LED: Blue/Green

Protection and Safety Features:

• Discharge Cut-off Threshold Voltage: 2.9V
• Overcurrent Protection Threshold: 3A (A sudden jump to >3A is considered a short circuit)

Charging Method and Interfaces:

• Charging Method: Linear Charging
• Input Charging Interface: USB (Micro USB or Type-C) and input pins (across the side of the USB port)
• Automatic Recharging: Yes

Environmental Specifications:

• Operating Temperature: -10°C to +80°C

Additional Notes:

• There are other and improved versions of the TP4056 module available in the market that may offer enhanced features and performance.

Connection Diagram of TP4056 Lithium Ion Battery Charger Module

Operating the Circuit on a USB Supply

When charging the battery using a 5V USB adapter via the USB port on the TP4056 module, the TP4056 handles the charging process with constant current and constant voltage. During charging, a red LED will be on to indicate the charging status.

Once the battery reaches a voltage level of 4.2V, the TP4056 module cuts off the charging process, and the green/blue LED turns on to indicate a fully charged battery. The TP4056 module provides the battery output with all the necessary protections (as mentioned in the specifications) through its OUT+ and OUT- pins. These pins are connected with an output filter capacitor and an output indicator LED (green) with a current-limiting resistor (R4 = 220Ω) and an output terminal header.

Operating the Circuit on a 12V DC Power Supply

When using a 12V DC power supply (such as from a solar panel or wall adapter) to charge the battery, the red LED indicates the presence of supply at the input through the DC jack. The battery charges through the TP4056 module similarly to when using a USB port. However, in this case, the power is supplied from the input pins (IN+ and IN-) through an IRFZ44N MOSFET (D2 is used to prevent reverse current).

While the battery is charging, if the output is connected to a load, the charging process won’t be interrupted. The output of the TP4056 is automatically isolated from the output through a 12V relay in the output section. The relay switches the output from the TP4056 (OUT+) to the output pin of the AMS1117 voltage regulator, providing the output from the AMS1117 voltage regulator in the output section.

How It Works

1. Input Filtering: The 12V input is filtered through capacitors (D1 used for reverse polarity protection). The 12V relay powers on (D3 used as a flyback diode) and switches the output as described.
2. Voltage Regulation: The LM7805 voltage regulator converts the 12V to slightly higher than 5V. A resistor (R1 = 1kΩ) is used instead of directly connecting the GND/ADJ pin of the LM7805 to ground to drive the gate of the MOSFET through a current-limiting resistor (R2 = 1kΩ).
3. MOSFET Switching: The IRFZ44N MOSFET provides higher current capacity to charge the battery through the TP4056 module’s input pins (IN+ and IN-). The AMS1117 voltage regulator and a supply indicator LED (red) with a current-limiting resistor (R3 = 470Ω) are connected to the output of the LM7805.

Key Considerations

• The resistor R1 at the GND/ADJ pin of the LM7805 voltage regulator ensures that the IRFZ44N MOSFET receives a stable gate threshold voltage (minimum 4V) despite any voltage drops across its drain-to-source path.
• Directly supplying 12V to the AMS1117 voltage regulator is not advisable as its maximum input voltage rating is 12V, with an optimal input around 8V to prevent excessive heat dissipation or damage.

After obtaining 5V 2A from the MOSFET, the TP4056 module charges the 18650 3.7V lithium-ion battery with constant voltage and constant current. The TP4056 indicates charging with a built-in red LED and cuts off charging at 4.2V, switching to a green/blue LED. The load at the output receives power from the AMS1117 voltage regulator as long as the 12V supply is connected.

When the 12V supply is disconnected, the relay switches back to the normally connected (NC) position, and the output load no longer receives power from the AMS1117 voltage regulator. The TP4056 then provides output with short-circuit protection, over-discharge protection, and other specified features.