DIY Power Bank With TP4056 and MT3608 (3.3V to 12V)

For any electronics project, we require a power source. In our previous article How to Run an ESP32 on Battery, we have discussed about the challenges with direct powering with battery. As most of the projects require 3.3V DC to 5V DC, we need some system which can be charged with a mobile charger and the output voltage can be adjusted for different configurations of the power supply plans. Building a DIY power bank with TP4056 and MT3608 is cheap and easy (the matter is about joining the modules). The components you need to build this DIY power bank are :

1. TP4056 module x 1
2. MT3608 module x 1
3. 3.7V Li Ion cell x 1
4. PCB as a board to hold the components x 1
5. Soldering iron
6. Multimeter
7. 2 pin PCB mount terminal block x 1
8. On Off switch x 1
9. 5V mobile charger x 1
10. LED x 1
11. 1K Resistor x 1

Here is the TP4056 Datasheet. Here is the MT3608 Datasheet. We are not going in to details of TP4056 (which is a charger circuit) and MT3608 (which is a DC-DC boost converter). The datasheets will give you a fair idea that the end output voltage will be regulated and linear.

TP4056 module costs $1, MT3608 module costs $1, 3.7V Li-Ion cell costs $4, 5V mobile charger will cost you $2. Rest of the components probably you have. So the total expenditure will not be more than $9. Within $10 you are getting a combined Chinese-Korean thing for your $10 ESP32.

How To Assemble Li Ion cell, TP4056 and MT3608 to Build a DIY Power Bank

The Chinese sellers suggested an over-simplified circuit diagram :

Below is our modified circuit diagram. You can use any of the circuit-diagrams because the result will not hugely differ. It is so easy that ASCII art is enough to draw it. We have added the resistor and LED to Li-Ion cell’s negative to complete it. GND of MT3608 added to GND to complete the circuit.

Li-ion cell’s positive is connected to the +ve of the output with MT3608’s positive ends and switch in-between.
Li-ion cell’s negative is connected to the +ve of the output with a diode and resistor in-between. LED and resistor will stop the backflow preventing a short-circuit.

Problem is that these circuits are difficult to use while charging. The charging process disables some protection features and may cause an overcharge situation. If you want the UPS feature, then this Instructable will help you :

Working on the Li-ion battery is potentially hazardous. If possible, you should use a UPS and connect a mobile charge to get a controlled output. There are UPS like APC Back-UPS BX600C-IN which are designed for Modem and other low power consuming electronic devices. The cost within $50 and provide complete peace of mind.