It s very likely that some bypassdiodes of your panels are damaged.
How to repair solar panel diode.
Bypass diode in a solar panel is used to protect partially shaded photovoltaic cells array inside solar panel from the normally operated photovoltaic string in the peak sunshine in the same pv panel.
When you repair overheated connections replace all metal parts that have been severely oxidized.
Those shaded solar cells become consumers of electricity instead of producers.
Then you will find a voltage that is 0v 1 3 or 2 3 of the voltage of the panels which are still o k.
In this video you will learn the importance of a bypass diode in solar panel learn how to connect a bypass diode to your own solar cells to improve the eff.
Blocking diodes will be of benefit in any system using solar panels to charge a battery.
This causes the solar panel to heat up and have some power loss.
If your solar panel will not exceed 2 1 2 amps of current then the 3 amp version is fine.
In multi panel pv strings the faulty panel or string has been bypassed by the diode which provide alternative path to the flowing current from solar panels to the load.
For solar panels the 3 amp and 8 amp diodes can be used for this purpose.
You should measure the open circuit voltage of each solar panel.
Bypass diodes inside a junction box of a solar panel provide a low resistance path for the current go around a series of solar cells that have been shaded.
Charred terminals on pv modules can be bypassed by soldering a wire directly to the metal strip that leads to the pv cells.
With a littly luck you can open the junctionboxes of the panels and change the damaged diodes.
In worst cases an electric arc will jump a gap melting metal and burning insulation to a char.
Solar panel repairing in urdu hindi part 2 سولر پینل ریپئرنگ جنکشن باکس sol.
The diode is wired in parallel with the cells.
Solar panels with more charge current than this would require a larger diode such as our 85 amp diode.