Solar Charge Controller

I’d like to build a charge controller for managing different battery voltage configurations without too much hassle.

Freifunk OpenMPPT

V1 - AVR-based

• GitHub Repo
• Notes: http://elektrad.info/download/Freifunk-OpenMPPT-Handbuch-26-August-2017.pdf
• https://www.isems.de/hardware/#2-der-freifunk-openmppt

V2 - ESP32

• GitHub Repo
• Talk at 36c3

References

Papers

• Design of an MPPT charge controller using a DC–DC buck-boost converter under system disturbances

Chips

If we don’t want to do “everything ourselves”:

• BQ25792 - I2C controlled, 5-A, 1-4 cell buck-boost charger with dual-input selector and USB PD 3.0 OTG output
  • BQ25798 - similar chip but with MPPT

Other projects

• DIYODE Magazine - ATtiny85-based Solar Charge Contoller
• Adam Welch - PWM85 Solar Charge Controller (also on Tindie)
• Solar Energy Generator - hackaday.io
• DIY Charge Controller - hackaday.io
• Arduino MPPT Solar Charge Controller
• SolarCharger SZBK07V2
• High Efficiency MPPT Solar Charger
• SunBoard - Charge Controller with MPPT & Bluetooth
• Mppt Solar Charge Controller 12V
• Skagmo - Maximum power point charger for solar panels - Github Repo
• Solar/LiFePo Multi-Controller with MPPT and ESP32