Find out how to correct its operation for Safe In-Circuit Charging.
The TP4056 chip is a lithium Ion battery charger for a single cell
battery, protecting the cell from over and under charging. It
has two status outputs indicating charging in progress, and charging complete. It also has a
programmable charge current of up to 1A.
You can use it to charge batteries
directly from a USB port since the working input voltage range is 4V ~
8V. However, remember the maximum current from a USB port is 500mA.
There are two types of common breakout boards for this chip:
One with only the charger chip on board.
One with three chips on board.
Here you are looking at the 3 chip breakout board (TP4056 - middle, DW01A - top right, and 8205A dual MOSFET - bottom right).
What you can learn here:
How to use the TP4056 breakout board.
How to use the TP4056 safely.
How the DW01A works on the TP4056 breakout board.
How to set temperature limits using the TP4056 TEMP input.
Lithium batteries can be dangerous if not charged properly and that's
why the TP4056 is useful as it stops over voltage and current charging by detecting specific voltage conditions.
There are a lot of circuits out there that show the
use of the TP4056 as both a charger and a load driver - Not Good.
If a load is attached to the battery while charging, then the TP4056
may not detect when the charge current has fallen to C/10. So it could
continue charging - this could be dangerous.
You should never use the TP4056 as a charger and as a load driverat the same time. When charging
the battery, switch off the load, and when loading the battery, switch off the charger.
Alternatively use a PMOSFET, a resistor and a Schottky diode (See page 2 on how to do this).
Lithium batteries can notabsorb overcharge - the current must be cut
off after charging. If not there could be
Constant Current / Constant voltage charging method.
The programming resistor (R3 or Rprog) is set to 1k2 which provides
1A programming charge rate or 1C. If your battery is not 1000mAh (1Ah),
then you need to remove R3 and replace it with the correct one following the
information in the table on the right.
TP4056 Status indicator LEDs
The table shows the state of LEDs for various charging states:
Red LED CHRG
Green LED STDBY
Vin too low; temperature of battery too low or too high; No battery.
BAT PIN Connect 10u Capacitance; No Battery.
Green LED bright, Red LED
TP4056 RPROG Current setting resistor
RPROG on the breakout board is R3.
TP4056 Charger Module Schematic
This is the schematic of the popular breakout board with label 03962A this shows the TP4056 pinout for the breakout board.
When charging a battery using the above board connect the battery to
B+ and B- and disconnect OUT+ and OUT- from your circuit. When using the
battery disconnect the 5V input and take the output voltage from OUT+
and OUT- to your circuit.
The following diagram shows a typical setup (from the datasheet). The
block diagram also shows the TP456 pinout for the 8 pin SMD device.
Here you can see the two status LEDs (CHRGn, STDBYn), Battery connection
(BAT), Current control connection (PROG) and TEMP connection. Some LI
batteries have an internal thermistor that you can connect as shown
above. In the breakout boards available generally TEMP is not used and
connected to Ground.
TP4056 reverse polarity protection
The TP4056 does not give you reverse polarity protection so
if you wire up the battery the wrong way round then you'll get smoke!
Actually, there is no TP4056 reverse polarity protection and the
DW01A battery protection IC (on the breakout board) is being used in the
wrong way (or not in the best way)! If used correctly the DW01A does provide reverse polarity protection for a battery.
On some breakout boards there are an extra 2 chips. One is the DW01A
and the other is a dual N Channel MOSFET required by the DW01A chip.
This chip provides battery protection but it is not used in the right
way on this board and so only provides short circuit protection (and
over current protection). It should provide all of the following:
Charger input protection
The CS pin is connected to the negative terminal of the charger input
(via a 1kÃ¢¦ resistor) and performs the following functions:
Short Circuit detector.
Over current detector.
Reverse charger detection (overstress high current?).
VCC and GND are connected across the battery where two voltages are detected:
Overcharge Detector (battery voltage too high).
Overdischarge Detector (battery voltage too low).
DW01A and TP4056 breakout Board
On the breakout board, the chip is soldered to the TP4056 so this can
never be connected the wrong way round at the "charger input". At the other side the DW01A does not protect
from connecting the battery the wrong way round!
This chip will not activate for battery voltage level problems (unless the TP4056 fails) since the TP4056:
Stops discharging at voltages below 2.9V; Here trickle charge activates. The DW01A threshold is ~ 2.4V; So it will never activate.
Stops charging at voltages above 4.2V. The DW01A threshold is ~ 4.3V; So it will never activate.
The only function that will operate is the overcurrent protection and
short circuit protection. These will activate at around 3A when using
the 8205A dual Mosfet.