
At long last I now have a computer that is solar powered. After placing the solar panel and running the solar panel wires on the roof yesterday, I completed running the wire into the house today. It quickly hooked up to the battery charger and battery. I then wired Odroid into this setup, and it transformed into the Sun Dragon.
Almost as soon as I had the setup connected, a storm moved in and the daylight dropped from over 100k lux to 5k lux. Using an ammeter I was able to see the current going to/from the battery. This would tell me if the battery was charging or discharging. If charging, the current would be positive as energy would be flowing from the solar panel into the battery. That means the Sun Dragon is running purely from solar power. If the current is negative, that means the solar panel isn't producing enough power to run the Sun Dragon by itself, and the battery is supplementing. Since a storm was overcasting the sky I was actually able to see this cutoff point. Right about 6,000 lux there is enough light to idle the Sun Dragon with no current going in or coming out of the battery. If the Sun Dragon begins do any work, however, this is no longer the case. Running a heavy CPU load on the Sun Dragon requires about 13k lux. Everything above that is energy in the bank.
Right now the Sun Dragon's battery has a full charge. I am going to allow this setup to run without the switch-over relay circuitry (it isn't finished) just to see how that goes. There has been plenty of sunlight lately so I shouldn't need it, and this will be a good first test for the system.
Almost as soon as I had the setup connected, a storm moved in and the daylight dropped from over 100k lux to 5k lux. Using an ammeter I was able to see the current going to/from the battery. This would tell me if the battery was charging or discharging. If charging, the current would be positive as energy would be flowing from the solar panel into the battery. That means the Sun Dragon is running purely from solar power. If the current is negative, that means the solar panel isn't producing enough power to run the Sun Dragon by itself, and the battery is supplementing. Since a storm was overcasting the sky I was actually able to see this cutoff point. Right about 6,000 lux there is enough light to idle the Sun Dragon with no current going in or coming out of the battery. If the Sun Dragon begins do any work, however, this is no longer the case. Running a heavy CPU load on the Sun Dragon requires about 13k lux. Everything above that is energy in the bank.
Right now the Sun Dragon's battery has a full charge. I am going to allow this setup to run without the switch-over relay circuitry (it isn't finished) just to see how that goes. There has been plenty of sunlight lately so I shouldn't need it, and this will be a good first test for the system.