Small solar systems

Sometimes you just need a small solar system to power some lights, radios, or a raspberry pi. This, is that! I have setup several of these at our glider field to power security cameras, radios, charge batteries, etc. It always goes like this: Solar panel -> charge controller -> battery.

I have used morningstar charge controllers for all the systems. We tried some off-brand ones and while they worked ok, they did not reliably disconnect the load at low voltage. That kills your batteries and there goes your cost savings! I like the morningstar SS-MPPT-15 controller. Since they are MPPT you can use them with the large, higher voltage panels cheaply available these days. I can typically get panels 250-300w output for around $100.

Data Logging

While not strictly necessary, this is a quick and fun little project that gives you some insight into how much battery capacity is being used. I have the following setup:

https://gist.github.com/AD7ZJ/525e2973fee1669ceeba2ad0223c2f78