32 diodes
I was thinking about the series blocking diode addition to my recent solar panel purchase: https://wb9kzy.blogspot.com/2026/04/make-or-buy.html Certainly there is a drop across the diode when the panel is charging, less than 250 mV with low current. But is it really needed ? Looking at the solar panel itself again there are 6 wafers, each wafer has 6 groupings of photodiodes with 6-5-5-5-6 diodes each or 32 total diodes in series. count the wider horizontal dark lines to determine the number of solar cells Per Wikipedia the output voltage of a silicon solar cell (diode) is .5 to .6 volts. Multiply 32 diodes times .56 volts gets to roughly 18 volts which is about the rated voltage: 21.6 volts divided by 32 is .675 volts so this sounds reasonable for a no-load situation. Now since the panel is charging a lead acid AGM / gel-cell battery the highest voltage that the battery could apply to those 32 diodes is roughly 13 volts: source: https://voltagebasics.com/lead-a...