DC -> DC -> DC Solar. With a single used solar panel, a few used batteries, and $40 in parts you can power your life, transportation and all. ESP32 Arduino + DC-DC buck-converter + Solar Panel + Battery = internet-connected, privately hosted smart solar MPPT power system.

Join the Discord Channel discord.gg/GtR3JShfGu to talk shop, get ideas, get help, triage issues, and share success!

This is an enthusiasts project at this point. If you'd like a plug-and-play system then MPPTs are a very cheap commodity device at this point.

This is for: ☀️ someone that's a battery-geek and wants to be able to charge any battery to any voltage (under your solar panel's mppt voltage), ☀️ someone that really wants to get an idea for how solar works, ☀️ someone who wants to do data science on their solar powered life, ☀️ someone who likes ESP32s as much as I do, and/or ☀️ you have a higher voltage solar panel / array (up to ~82V) and can't use anything else. Tell us about your setup/ideas in the Discord Channel discord.gg/GtR3JShfGu and we'll help!

A solar charge controller. A cheap off-the-shelf power supply + a cheap WiFi microcontroller.

A dashboard view using Grafana (for charts) and InfluxDB (for data storage)

• Costs less than $40 in total parts
• Works with 12 - 82VDC Solar Panels, (enabling big and efficient series strings of panels!)
• Works with 3 - 60VDC batteries. Directly charge your high-voltage eBike batteries!
• Now runs with different power supply options for extra flexibility
• Is open source, modify it as you wish!
• Connects with open source MQTT protocol. Add to your smart home or chart data with beautufil graphs.
• Lets you own your own data
• Gives you graphs and charts about your system from anywhere

It's a MPPT, Maximum Power Point Tracking solar controller which means you get far more energy from your panel than if you connected it directly and full control of your charge profile– a requirement for lithium cells.

Most things in your life run on DC, you're just wasting power converting AC->DC with a trillion little 'wall-worts'. Get a couple super-efficient DC-DC converters and power:

• Your ebike, escooter... eunicycle? I use a cheap high-power DC-DC boost converter
• Your 3D printer! They mostly all run at 24V, peak ~8A (when the bed is heating)
• Your lights– led arrays, fairy lights, recessed lighting
• Your laptop (I use this USB-C power adapter which accepts 12V up through the 28V max of my lifepo4 packs- and will output 20V/3A. My macbook is very happy)
• Your router & cable internet modem! When your power goes out your cable connection almost never does too. I've provided internet to my whole building during our recent blackout. These devices usually run on 12V, those DC-DC converters cost pennies.
• A classic AC inverter to power your fridge, washer-dryer, etc.

Head over to the parts list and build steps page! Seriously, ping the Discord Channel discord.gg/GtR3JShfGu with your setup/plans first. I want to get you on the right track.

Here's a page on the story of this project and the reason for its being