What is going o here? 6 bad panels?

[Woggs1]

I bought 6 used panels and they are testing at 65v and 11.5 amps so volts times amps is 750 watts or so. But these are 190 watt panels. What am I doing wrong, or are they bad panels? All 6? Here is a video of my test:

 

[gnubie]

Not sure how you are getting 11.5 amps as a single panel, from the spec sheet, simply should not be capable of that current. Perhaps your meter is crook.

 

[Rider]

You can't use the measured voltage/amps to determine the panel rated wattage. These are the specs from my panel, 270W. If you multiply measured volts/amps (38.6Voc and 9.03Isc), you'll get 348.6W, way more than the rated 270W. However, if you multiply the Optimum Volts and Optimum Amps (Vmp and Imp), 31.4V x 8.6A = 270.04W. Your label may not show the Optimum values, but that's where the panel wattage is derived from.

Maximum Power: 270W	Maximum System Voltage: 1000 VDC (UL)
Optimum Operating Voltage (Vmp): 31.40V	Open-Circuit Voltage (Voc): 38.60V
Optimum Operating Current (Imp): 8.60A	Short-Circuit Current (Isc): 9.03A

 

[SolarRat]

You are going to blow up your meter trying to measure amps across a circuit like that, and it won't work anyway. You need to put the meter in series on the + or - cable, and it must be under load.

 

[Supervstech]

I bought 6 used panels and they are testing at 65v and 11.5 amps so volts times amps is 750 watts or so. But these are 190 watt panels. What am I doing wrong, or are they bad panels? All 6? Here is a video of my test:

I’ve never seen a panel with ssA so close to Ipmax... I’m guessing here, but the label is likely wrong.
Tie them to your CC and see the wattage you can get out under load.

 

[bulrush]

Panels are rated based on lab conditions which are rarely, if ever, met in real life. So ratings on the panel exceed real life results. I look at panels and start at 80% of rating, then go down from there when I control for overcast days. The 80% of rating will only happen on a perfectly sunny day, with the panels in the perfect angle to the sun, in direct full sunlight.

Panel efficiency also goes down when they get hot.

You might also have the occasional disconnected or corroded silver ribbon inside the panel since these are used panels.

Your panels look fine.

 

[PHoganDive]

If you've overloaded the meter at some point, it may have blown the internal fuse for the current measurement....this will lead to very inaccurate current measurements...ask me how I know...