Yesterday, I decided to change my installation a bit, and in one single day I already have results of it.
Basically, I put a better solar controller, which allowed me to reduce the complexity of the installation a lot.
Solar panels (36V) → Buck converter (36V to 12V) → Solar controller (12V) → Battery (12v) → Buck converter to USB (12V to 5V) → Raspberry PI
Solar panels (36v) → New solar controller (36V to 12V) → Raspberry Pi and Battery
The new solar controller can receive up to 50V and up to 30A, which is way more than my panels would ever product. It also has a USB output:
So, I eliminated:
- The buck converter from the panels to the controller, and
- The buck converter from the controller to usb.
The efficiency improvement is palpable. As you can see from my uptime data on my github (see the sqlite3 file), now the raspberry is able to run through the whole night, while before it would turn off in the middle of the night, when the battery would be depleted.
One difference, though, is that I stopped running BFGMINER (it was not mining, just on), so I have to investigate this as well.