Introduction to TP4056 :
TP4056 is a fully linear (constant current/constant voltage) charger for a single cell Li-ion/LiPo (Lithium Polymer) batteries. Its low external component count and small outline package make it perfect for portable applications. Additionally TP4056 is compatible with micro USB as well as adapter. Moreover it also has features like Automatic recharger, under voltage lockout, current monitor and two LEDs for indication of charging mode and termination signal. TP4056 schematic circuit diagram is here
TP4056 module schematic diagram
Unlike ordinary Nickel-cadmium battery that has 1.2V /cell, LiPo battery cells are graded as 3.7V per cell. This enables us to make a rich power bank by using fewer cells. Normally two or more cells are connected in series however in big RC modules this number increases to 6 cells pre pack.
How to charge a TP4056-LiPo battery?
Charging a LiPo battery requires a special charger precisely designed for Li- chemistry. However assembling of Lithium ion battery charger using TP4056 IC is not an easy task for a normal person having low SMD embedding practice. But don’t worry, for such persons an alternative solution is that, just buy the prepared module from eBay and hack it to complete the module.
For potential charging of a 3.7V Li-ion battery, it must be charged at continuous current of 0.2 -0.7 times the cell’s capacity, until its voltage becomes 4.2 V. after that it should be charged at continuous voltage mode until it the charge current drop to 10 percent of its preliminary charge rate. Charging can’t be terminated at 4.2 volts b/c at this voltage only 40 to 70% of full capacity is reached. TP4056 is responsible for all of this.
Features of TP4056 Charger:
- Upto 1000mA Programmable charging current
- Doesn’t require a blocking diode
- Completely linear charger in small outline package for singal cell Li-ion battery
- Constant voltage and Current
- Recharges the battery through USB port
- PreSet 4.2 volt charging voltage
- Automatically recharging ability
- Termination charge =C/10
- It is ideal for DiY applications.
How to use TP4056 module?
- For power you will give a micro USB connection to IN- and IN+ pads of the module as shown below
- To charge the cell connect it to the B- and B+ pads of the TP4056 module
- Load will be connected to the Out + & out – pads of the module.
- During charging disconnect the load
- Glowing red LED shows that charging is under process where as the green LED is on when charging completes.
- Never try to charge the LiPo battery at rate above 1C.
TP4056 module Specifications:
- Input voltage = 5V (-0.3 ̴ 8V)
- Complete charging voltage= 4.2V
- Charge current (by default) = 1A. However this value can be change by changing the different value resistor at left bottom corner of the board besides the IN- pad. A table of matching values for Rprog and battery current IBAT is available in TP4056 datasheet at the end of the article
TP4056 module applications:
- GPS, PDA (personal digital assistant), Cell phones
- Charging Cradles and Docks
- Portable devices like Digital Cameras
- Chargers, USB bus hubs