• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar

Circuit Ideas for You

Get free circuit ideas online.

  • Home
  • Privacy Policy
  • About
Home » DIY Solar Battery Charger Circuit

DIY Solar Battery Charger Circuit

Last updated on 7 October 2025 by Admin-Lavi Leave a Comment

This is a small DIY Solar Battery Charger Circuit project.

It charges one 3.7V lithium battery using sunlight.

We can use solar cell, TP4056 charger board, one diode, one switch and one boost converter module..

This circuit make 5V power for battery and mobile charging.

Graph for lithium battery charge over time:

Simple Li-on Battery charge cycle graph diagram

This graph show how lithium battery charge over time.

At start the battery take high current and voltage go up slowly, this is constant current stage.

When voltage reach around 4.2V, charger hold voltage steady and current start to go down and this is constant voltage stage.

When current drop very low then charging stops and charge gets terminated.

This is how TP4056 or other Li-ion charger work safely to charge 3.7V battery.

Circuit Working:

DIY Solar Battery Charger Circuit Diagram

Parts List:

Component NameQuantity
TP4056 Battery Charger Module1
18650 Lithium Battery1
SPDT Switch1
1N4007 Diode1
Solar Panel 5V1
Voltage Booster Module1

Solar panel make electricity from sunlight.

Diode stop battery power go back to panel at night.

TP4056 board charge the 18650 battery safe.

SPDT switch control charge or use mode.

Voltage booster take 3.7V from battery and make 5V for mobile or USB device.

How to Build:

To build a DIY Solar Battery Charger Circuit follow the below steps for connections:

  • Assemble all the parts as shown in circuit diagram
  • Solar cell positive connect to diode anode.
  • Diode cathode connect to TP4056 IN+.
  • Solar cell negative connect to TP4056 IN-.
  • TP4056 OUT+ connect to battery positive.
  • TP4056 OUT- connect to battery negative.
  • Switch middle pin connect to battery positive.
  • Other side of switch go to boost converter input +.
  • Boost converter input – connect to battery negative.

Conclusion:

This DIY Solar Battery Charger Circuit is simple and cheap.

It is good to learn small solar project.

We can use it to charge phone, light or small gadget from sun.

It is safe to use and nice for beginner people.

References:

Solar charger IC for NiMH just like the TP4056 for LiPo

Filed Under: Battery Charger Circuits, Solar Circuits

About Admin-Lavi

Lavi is a B.Tech electronics engineer with a passion for designing new electronic circuits. Do you have questions regarding the circuit diagrams presented on this blog? Feel free to comment and solve your queries with quick replies

Previous Post: « Simple Solar Mobile Charger Circuit

Reader Interactions

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Primary Sidebar




Categories

  • Alarm Circuits (34)
  • Amplifier Circuits (67)
  • Arduino Projects (59)
  • Audio Circuits (98)
  • Automobile Circuits (19)
  • Battery Charger Circuits (50)
  • Free Energy (13)
  • Heater and Temperature Controllers (10)
  • High Voltage (1)
  • Indicator Circuits (41)
  • Inverter Circuits (15)
  • LDR Circuits (17)
  • LED and Lamps (118)
  • Meters and Testers (29)
  • Motor Controllers (18)
  • Oscillator Circuits (34)
  • Power Supply Circuits (93)
  • Remote Control Circuits (7)
  • Security and Protection (26)
  • Sensors and Detectors (98)
  • Solar Circuits (19)
  • Timer Circuits (31)
  • Transistor Circuits (57)
  • Transmitter Circuit (14)
  • Tutorials (5)
  • Water Level Controller (4)

Recent Posts

  • DIY Solar Battery Charger Circuit
  • Simple Solar Mobile Charger Circuit
  • Simple 3.7V DC to 220V AC Inverter Circuit
  • Smart Energy Meter Circuit with Arduino UNO
  • LED Binary Counter Circuit

Recent Comments

  1. Admin-Lavi on Constant Voltage, Constant Current Battery Charger Circuit
  2. Bill on Constant Voltage, Constant Current Battery Charger Circuit
  3. Admin-Lavi on Long Range FM Transmitter Circuit (2km)
  4. Sina on Long Range FM Transmitter Circuit (2km)
  5. Admin-Lavi on Long Range FM Transmitter Circuit (2km)

Copyright © 2025 | New Circuit Ideas