Due to the lack of replies, im guessing the answer must be no. Cause I think the Arduino cant take 21v 5w input and no-one wants the headache of transistors.
Can I use transistors to switch on and off the charge either when the battery is full or when the solar pannel isnt producing enough power? Been trying to find out about 1N60 Zenner diodes. Is the lm 393 any help for compairing against a known voltage or something? I have switches and leds too, maybe good for a shunt or something??? Got about 150 1N4148's
ps... Would be good if I could just add aditional solar pannels without having to change the design.Really need something I can throw together in about 2 mins.