Introduction: Lithium Ion Polymer Battery AIO Charger-protector-booster
We all have spare/salvaged LiPo batteries, which we have either recovered from old laptop batteries or purchased new batteries.
To use them we all use commercially available modules for charging, protecting and for boosting the voltage to 5V for using them to power our USB devices like charging phones, power banks, charging Bluetooth headphones and speakers, running arduino and Esp8266-NodeMCU boards and other stuffs.
But these boards are separate and need separate wiring and its time and space consuming.
So, today we will design, fabricate and build an All-in-One LiPo battery charger with protection circuit and a 5-Volt boost circuit board.
MICRO USB connector - 1
Toggle Switch - 1
FS312F-G IC - 1
Red LED - 1
Green LED - 1
Resistor 7.5K - 1
Resistor 100 - 1
MT3608 IC - 1
FS8205 IC - 1
Capacitor 10uF - 1
Inductor 22uH - 1
Resistor 2K - 2
Diode SS34 - 1
Resistor 1K - 3
Capacitor 100nF - 1
TP4056 IC - 1
Capacitor 22uF - 2
Step 1: Schematic Design
I have used EasyEDA software to design the board. It’s easy and fun to use and has the footprint libraries of most of the components.
FS312F-G IC –
Protection IC for Li-ion/polymer rechargeable one-cell batteries
• Low supply current
• Overcharge detection voltage: 4.25±0.025 V
• Overcharge release voltage: 4.145±0.05 V
• Over discharge detection voltage: 2.90±0.08 V
• Over discharge release voltage: 3.0±0.08 V
• Over current detection voltage: 150±30 mV
• Short circuit detection voltage: 1.35 V
• Delay time generated by the internal circuit
• Charger detection voltage: -1.35 V
• Reset resistor for over current protection: >500KΩ
• Wide supply voltage range: 1.5 ~ 9.0 V
MT3608 IC –
The MT3608 is a constant frequency, 6-pin SOT23 current mode step-up converter
• Integrated 80mΩ Power MOSFET
• 2V to 24V Input Voltage
• 1.2MHz Fixed Switching Frequency
• Internal 4A Switch Current Limit
• Adjustable Output Voltage
• Internal Compensation
• Up to 28V Output Voltage
• Automatic Pulse Frequency Modulation Mode at Light Loads
• Up to 97% Efficiency
FS8205 IC –
Dual N-Channel Enhancement Mode Power MOSFET
TP4056 IC –
Constant-current/constant-voltage linear charger for single cell lithium-ion batteries
· Programmable Charge Current Up to 1000mA
· No MOSFET, Sense Resistor or Blocking Diode Required
· Charges Single Cell Li-Ion Batteries Directly from USB Port
· Preset 4.2V Charge Voltage with 1.5% Accuracy
· Automatic Recharge
· Two Charge Status Output Pins
· C/10 Charge Termination
· 2.9V Trickle Charge Threshold (TP4056)
· Soft-Start Limits Inrush Current
Inductor 22uH -
I have used a 1206 inductor but a SMD power inductor is better option.
Datasheet of all components are linked here.
Step 2: PCB Layout and Designing
I have used EasyEda to design the 2-layer PCB.
It’s easy and fun to use and has the footprint libraries of most of the components.
If anyone wants i can always post the gerber files for you.
Step 3: Ordering the PCBs
Now we have got the PCB design and it’s time to order the PCB’s. For that, you just have to go to JLCPCB.com , and click on “QUOTE NOW” button.
JLCPCB are also sponsor of this project. JLCPCB (Shenzhen JLC Electronics Co., Ltd.), is the largest PCB prototype enterprise in China and a high-tech manufacturer specializing in quick PCB prototype and small-batch PCB production. You can order a minimum of 5 PCBs for just $2. To get the PCB manufactured, upload the gerber file you downloaded in the last step. Upload the .zip file or you can also drag and drop the gerber files. After uploading the zip file, you’ll see a success message at the bottom if the file is successfully uploaded. You can review the PCB in the Gerber viewer to make sure everything is good. You can view both top and bottom of the PCB. After making sure the PCB looks good, you can now place the order at a reasonable price. You can order 5 PCBs for just $2 plus shipping. To place the order, click on “SAVE TO CART” button. My PCBs took 2 days to get manufactured and arrived within 20 days using standard registered post delivery option. There are fast delivery options also available.PCBs were well packed and the quality was really good.
JLCPCB is now offering SMT assembly service that too at a very reasonable price and after trying it I must say that they are doing excellent work and their craftsmanship is comparable to any other commercial PCB manufacturing and assembly service all over the world.
Their backend team is so efficient and through that they will check each and every design and component placement and will inform the customer about required changes in design or about wrong placement and polarity of the components and correct the minor issues at their end itself.
Step 4: Assembly and Working
- R2 and R4 resistor forms a feedback network for the boost circuit and has been calculated to give 5V
- L1 is 1206 SMD variant, its better to use a power inductor to get more current output, have spare terminals for the same
- LEDR (RED) is for charging indication
- LEDG (GREEN) is for charging done indication
- Max input current for TP4056 should be 1-1.5 Amps as above that the IC gets really hot and there is risk for damaging it. Also as its a linear converter IC more current at higher voltage means more power loss as heat and reducing the efficiency overall
- Added VBUS and GND1 female headers for connecting wires directly instead of the MicroUSB port
- Toggle switch controls the output of 5-Volt terminals
- This is pass-thru charger and thus will provide power to 5-V terminal even when charging
PS: The Idea and Design is inspired by greatscott.