When you use a charge controller that is what it is doing anytime the battery bank is full tapering off the.
Burn marks on solar panels.
Badly soldered connections cause low resistance in the part of the panel that receives the power generated by the cell.
Mark having solar panels in the sun without a load on them should not damage them.
This is a sign of a burnt terminal.
You will need to replace all metal parts in the terminal.
The current output from the whole panel is limited to that passing through the weakest link cell.
If you work in the solar panel installation business long enough you ll inevitably come across solar panels with strange brown spots.
Hotspots on panels are mainly caused by badly soldered connections or are a result of a structural defect in the solar cells.
When you examine the terminal you will more than likely find signs of oxidation.
If even a small section of a photovoltaic panel is shaded for example by the branch of a tree there is a very significant drop in power output from the panel.
This is because a pv solar panel is made up of a string of individual solar cells connected in series with one another.
Just like a car battery solar panel system battery terminals can burn out.
Typically they are in the same exact place on multiple solar panels.
A burnt terminal can be cause by wiring too many panels to one terminal.