Ampage from solar

[Jev88]

Fairly dull day today.
When I add a second 100w panel should I see a significant Ampage reading increase on my solar controller?
Tested individual panels for voltage unloaded - 21.4V.
They are now in parallel but still seeing 0.6amps from basic controller as it is very dull.

 

[68c]

If your batteries are fully charged and no load you may not see much extra amperage. Try turning on all the interior lights, TV etc then recheck using one and then both panels.

 

[funflair]

Can your controller take the input from two panels, as in can it handle 200w, otherwise as above.

Martin

 

[SandraL]

Have you added blocking diodes?
Probably not fitted on the first panel, but with 2 panels in parrallel you will need one for each panel. Without them you will get reduced output.

In our case we had 100w and 150w panel. Reduced output until diodes fitted.

 

[Jev88]

Have you added blocking diodes?
Probably not fitted on the first panel, but with 2 panels in parrallel you will need one for each panel. Without them you will get reduced output.

In our case we had 100w and 150w panel. Reduced output until diodes fitted.

That's a new one to me. Both panels have their own control type thing on the back where the wires emerge from. Can you point me to these diodes?

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[DBK]

That's a new one to me. Both panels have their own control type thing on the back where the wires emerge from. Can you point me to these diodes?

Blocking diodes are to prevent current flowing back into the panel. I wouldn't worry about them. In theory with two panels in parallel and if one was completely shaded the other panel might lose some power trying to push current into the shaded one.

I don't think you can judge what your panels are now doing until you get some sunshine and the batteries have been discharged a bit.

The only thing you can check until then is the controller should be holding the batteries at about 13.7 to 13.8 volts even with clouds, assuming they are normal lead acid batteries.

 

[Jev88]

Blocking diodes are to prevent current flowing back into the panel. I wouldn't worry about them. In theory with two panels in parallel and if one was completely shaded the other panel might lose some power trying to push current into the shaded one.

I don't think you can judge what your panels are now doing until you get some sunshine and the batteries have been discharged a bit.

The only thing you can check until then is the controller should be holding the batteries at about 13.7 to 13.8 volts even with clouds, assuming they are normal lead acid batteries.

Thanks for that.
Only one 12 month old leisure battery currently. Will have two when funds allow.
Battery is at 12.8v now it is dark after 3 months of very little use etc.... With just the original 100w panel feeding it whilst on storage.

 

[Lenny HB]

What you need to do is either at night or with the panels disconnected turn some stuff on in the van and run the batteries down a bit say to 75 %. Then you will be able to see how well your solar is working, at this time of year even on a bright sunny day 200 watts will only give about 2-2½ amps.