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Drop in solar panel voltage to zero when connected to load (Read 6328 times)
electron
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Re: Drop in solar panel voltage to zero when connected to load
Reply #1 - May 11th, 2012 at 2:28am
 
Nitin wrote on May 10th, 2012 at 8:05pm:
Solar panel is showing Open circuit voltage & short ckt current.But when we are connecting it to load voltage drops to zero.So what might be the reason?

Depends on what you see for short circuit current.

How many watts is the panel listed for?

Assuming that you are in full sun, for example, a 60W panel would typically say on the sticker around 3.8A shorted (listed as "Isc" typically).

The problem is if your load tries to pull 3.8A then your voltage will drop to close to zero.

There is usually a rating for full power amps and volts, typically "Vpmax" (volts) and "Ipmax" (amps), that's the maximum power point of the panel in a really good perfect summer sun which you don't get every day, so your AMP results will be a little lower than that at that voltage.

So if your panel reads close to the "sticker" amounts normally but with the load connected it drops, then your load wants too much power basically.

You want to measure the amps while connected to your load and see what it is. Put your meter in series with the load to measure amps.

You should have some test loads sitting around if you are going to keep messing with solar. Old car light bulbs are great for this. A typical "parking" light is around 1.3A, just measure it with your meter and a 12V car battery and maybe stick a piece of tape on it with the amp rating to remind you.

You can keep adding on light bulbs, measure things with a meter and see how the panel is doing under load.

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« Last Edit: May 11th, 2012 at 2:28am by electron »  
Nitin
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Drop in solar panel voltage to zero when connected to load
May 10th, 2012 at 8:05pm
 
Solar panel is showing Open circuit voltage & short ckt current.But when we are connecting it to load voltage drops to zero.So what might be the reason?
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« Last Edit: May 10th, 2012 at 8:10pm by Nitin »  
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