A dependable and effective method for charging lithium-ion batteries particularly ones with a nominal voltage of 3.7V is the TP5000 battery charger circuit.
This charger offers fine control over the charging process and has a small form thanks to the use of the TP5000 integrated circuit.
By include necessary passive parts like diodes, resistors, capacitors and inductors, this circuit improves safety throughout the charging cycle while also guaranteeing peak performance.
Capacitors filter and stabilize the input and output signals, while resistors assist in setting the charging current and voltage levels.
In order to store and convert energy and maintain the circuits efficiency, the inductor is essential.
To further guard against damage to the battery and charger, a diode is included to stop reverse current flow.
An LED indication improves user engagement and convenience by giving a visual hint regarding the charging state.
The main elements and features of the TP5000 charger circuit are described in this introduction, which also highlights the chargers adaptability and efficiency in handling lithium-ion battery charging applications.
This circuit is a useful tool for effective energy management and battery maintenance, regardless of whether it is being used for hobby projects or more intricate electronic systems.
Circuit Working:
Parts List:
| Component | Value | Quantity | Remarks |
|---|---|---|---|
| Resistors | 1k | 1 | 1/4 watt |
| 0Ω | 1 | 1/4 watt | |
| 0.1Ω | 1 | 1/4 watt | |
| Capacitors | Electrolytic | 10μF 25V | 3 |
| Ceramic | 100nF | 1 | |
| Semiconductors | IC | TP5000 | 1 |
| Inductor | 47μH | 1 | |
| Diode | SS34 | 1 | |
| LEDs | Red and Green 5mm 20mA | 1 each | |
| Li-ion Battery | 3.7V | 1 |
The TP5000 integrated battery charging IC adopts a switching buck converter layout.
It can now withstand greater currents without overheating thanks to this.
The input voltage, which should range from 4.5V to 9V, is connected to the VIN pins 1, 2, and 16.
The LX pins 3, 4, 5 function as the output terminal for the external inductor and link to the battery charging current input.
The VREG pin 10 serves as an internal power supply, while the battery pin 9 is connected to the batteries positive terminal.
The input terminal of the battery is monitored for temperature using the TS pin 11.
An external resistor supplies a constant current that is set by the RTRICK pin 12.
When the lithium iron phosphate 3.6V off state is activated, the CS pin 13 monitors low end input levels for the TP5000.
With an active low output, the STDBY pin 14 signals when charging is finished.
The charging state is shown by the CHRG status pin 15, and pins 14 and 15 are connected to LEDs.
While the 0.1Ω resistor restricts the charging current to 1000mA (1A), the 0Ω jumper sets the pre-charge or trickle current to 10% of the battery current.
Formulas:
Following are the relevant formulas for Simple Battery Charger Circuit utilizing the IC TP500:
Charging Current Calculation:
Icharge = Vin−Vbat / R
where,
- Vin is 6V
- Vbat is 3.7V
- R = R2
Capacitance Selection:
Calculating the value of capacitors may be done using the required ripple voltage:
C = I x t / ΔV
where,
- I is the charging current,
- t is the time in seconds for which the capacitor discharges
- ΔV is acceptable voltage ripple.
Inductor Current Ripple:
ΔIL = Vin x D / f x L
where,
- D is the duty cycle
- f is the switching frequency
Verify the component values and settings against the TP5000 datasheet to ensure that they match the precise operation parameters and restrictions.
How to Build:
To build a Simple Battery Charger Circuit using IC TP5000 following steps need to be followed for assembling process:
- Gather all the components as shown in the above circuit diagram.
- Connect pin 1 of IC TP5000 to positive supply of input +6V.
- Connect pin 2 of IC TP5000 to pin 1.
- Connect pin 3 of IC TP5000 to pin 4 and pin 5 .
- Connect pin 4 of IC TP5000 to one terminal of 4.7uH indicator coil and the other end to positive terminal of capacitor C2.
- Connect a cathode of diode D1 SS34 to pin 3,4 and 5 of IC TP5000 and one terminal of 4.7uH inductor coil.
- Connect pin 6 of IC TP5000 to negative leg of capacitor C4 10uF and one terminal of capacitor C3 100nF.
- Connect pin 7 of IC TP5000 to pin 6.
- Resistor R2 0.1ohms is connected between pin 8 and pin 9 of IC TP5000
- Connect pin 9 of IC TP5000 to the positive of the 3.7V battery which needs to be charged, and connect the negative of the battery to the GND supply of the circuit.
- Capacitor C3 100nF is connected pin 10 of IC TP5000 and GND.
- Connect positive terminal of capacitor C4 10uF from pin 9 of IC TP5000 and negative terminal to GND.
- Connect pin 11 and pin 13 of IC TP5000 to GND.
- Connect pin 12 of IC TP5000 to one terminal of resistor 0 ohms and other terminal to GND
- Connect the cathode of STDBY green LED to pin 14 and connect the cathode of CHRG red LED to pin 15, and connect the anode of both the LEDs to positive of +6V through R1 1k resistor.
- Connect pin 1, 2 and 16 of IC TP5000 to the positive supply.
- Connect the positive terminal of capacitor C1 10uF to the positive line of +6V, and negative terminal to GND.
Conclusion:
A flexible and effective method for charging lithium-ion and lithium-iron phosphate batteries is the TP5000 battery charger circuit.
Since of its switching buck converter architecture, it is more reliable since it can handle greater currents without overheating.
The TP5000 offers versatility for several uses with features including temperature sensing, consistent current regulation, and adjustable charging conditions.
Users may optimize performance and safety by customizing the charging procedure to fit individual battery requirements by making minor tweaks to resistors and jumpers.
Overall, this circuit is a useful option for effective battery management in both home and business environments.
References:
Lithium Ion Battery and Warm Circuit Board
TP5000 Single-Cell Lithium Battery Charge Module Review [FAQ]