I built a solar panel charge controller from instructables with an easy to read schematic and for some reason my battery charges up to a certain point and then loses charge again. That leads me to ask a couple of questions given that i am very new to this.
My Setup: 10W solar panel, 12v7A Lead Acid Battery, Arduino Nano and all components from above schematic except for the load at this point.
More details on solar panel specs: Solar Panel 10W • Vmax P = 17.2V • Imax P = 0.57A • Voc = 21.6V • Isc = 0.83A • 396x348x25mm
- Before I connect my solar panel my panel's voltage sits around 20volts (with volt meter) but straight after I connect it to the circuit, the voltage drops. Is this because there is now current and that reduces the voltage?
- At a certain point (around 12.4 volts) my battery stops charging and actually starts losing voltage. Could this be because the current supplied from the solar panel is not enough to charge the battery? If not, any other ideas?
- Does it make sense that the Arduino, solar panel, batteries and output voltage ground are all connected together?
- At what voltage would I actually charge my batteries when in bulk charging mode (99% pwm)? Does it have to be more than the current voltage of the battery and by what margin?
Thank you very much for the assistance and please bear with me, I am new to this.