makerPower™ MPPT Solar Charger

makerPower MPPT Charger PCB
Available to buy at Tindie.

As of 2/2023, the charger supports 4-cell 12V LiFePO4 batteries (new firmware version 2.0).
The MPPT Solar Charger is an intelligent solar charging system and power supply designed to provide power to IOT-class devices (Arduino type through Raspberry Pi 3 type) in remote, solar-powered environments. It manages charging a 12V AGM lead acid or LiFePO4 battery from common 36-cell 12V solar panels. It provides 5V power output at up to 2A for systems that include sensors or communication radios. Optimal charging is provided through a dynamic perturb-and-observe maximum power-point transfer converter (MPPT) and a 3-stage (BULK, ABSORPTION, FLOAT) charging algorithm. A removable temperature sensor provides temperature compensation. Operation is plug&play although additional information and configuration may be obtained through a digital interface making it an ideal companion to intelligent or internet-connected devices.

The use of commonly available 12V solar panels and AGM or LiFePO4 (UPS) lead-acid batteries allows for an inexpensive system capable of operating systems 24/7 even in inclement weather and over a wider temperature range than systems using other battery technologies.


• Reverse Polarity protected solar panel input with press-to-open terminal block
• Fused battery input with press-to-open terminal block
• Maximum 2A at 5V output on USB Type A power output jack and solder header
• Automatic low-battery disconnect and auto-restart on recharged battery
• Temperature compensation sensor with internal sensor fallback
• Status LED indicating charge and power conditions, fault information
• I2C interface for detailed operation condition readout and configuration parameter access
• Configurable battery charge parameters
• Status signals for night detection and pre-power-down alert
• Night-only operating mode (switch 5V output on only at night)
• Watchdog functionality to power-cycle connected device if it crashes


• Remote control and sense applications
• Solar powered web or time-lapse camera
• Night-time “critter cam"
• Solar powered LED night lighting controller
• Power supply with battery backup for Raspberry Pi Server or Router
makerPower with 7 and 18 AH batteries and solar panel
makerPower block diagram
makerPower diagram showing connections
Stacks Image 18

Downloads and Links

GitHub repository with documentation, software including an Arduino library, linux daemon for Raspberry Pi and desktop monitoring application, design files and complete demo applications.
The development of the project documented at
The product was launched as a project on the Crowd Supply website.
Available at

Demonstration Projects

Documented in the github repository.
makerPower solar webcam in the woods
Design files for laser-cut plastic inserts for an off-the-shelf enclosure useful for making a remote webcam.

Configuration for the motioneyeos webcam distribution to integrate the mpptChgD daemon for solar information logging and automatic power management.
Adafruit IO Dashboard showing data from makerPower powered esp8266
Interface with esp8266 using the Arduino library and Adafruit IO for remote monitoring.
Demo with DIYgeiger, Photon and makerPower
Interfacing a DIYgeiger gigger counter with a Particle Photon and for remote radiation monitoring.
makerPower controlling LED lighting
Using the makerPower charger as a stand-alone controller for solar powered LED lighting.
makerPower as a UPS with Pi + HDD
Working with a common laptop power supply to implement a long-lasting DC Uninterruptible Power Supply (UPS).