Apologies for this very simple question but I need a good simple arduino based data logger so I decided to order one of the datalogger shields as it will work well with my setup.
What I want to do is measure the power output of a solar panel over a day, so what I think would be the easiest would be to measure the voltage coming out of the panel and then measure the voltage drop across a good tolerance resistor to get the current, then I'd have the power output, would that be the easiest way?
The problem is the inputs from the arduino won't be able to take the 10W or so coming out of the panel and I want to charge a battery with the output, so would a voltage divider do the trick? If so should I just make one myself or are there chips I can buy that can do the job better?
Apologies again but I'm pretty new to all this so I thought there would be no harm in asking!