I am looking for some advice on how to improve my current system. In brief, I live off grid but am a keen drone enthusiast. As such, I am constantly having to charge these 0.9 amp, 7.4 volt, 2 cell Lithium Potassium batteries.
A friend helped me to rig up a little system with a 45 watt solar panel and a supercap bank featuring 6x 2.7 volt, 500 F units.
This system is excellent, being very much offgrid, and allows me to charge the batteries very easily. However, there is one catch. I have to be careful to unplug the solar panel so that the voltage coming through does not exceed 16.2 volts (and blow up). This means that I am constantly having to march back and forth to check & plug/unplug the system. Also means that I can never leave the house and go to work to come home to fully charged batteries.
I have included photos of the set up below.
I would like to put in some sort of resistance between the supercaps and the solar panel so as to limit the voltage coming in from the solar panel to 16.2 volts. But as am not a very tech-lingual, I have no idea what the part I need is called. So can someone advise me on the component I would need? I gather it would be either some sort of DC voltage stabilizer but I am not really sure...
edit: could not post all the photos as have 0 rep being a new user. Posted the ones I felt were most useful.