Annie Hope wrote:Just received them a few days ago, and not sure what to do from here to test them for efficiency.
Yes well, gosh. Since I have lived off grid all solar for 15 years, I have gone through trying to outsmart the systems like this so many times that my best advice is, YOU DO NOT NEED TO REINVENT THIS WHEEL.
Anyway you are not yet equipped to test " efficiency" sorry but unless you are an EE with a few hundred thousand $ of equipment at your disposal, that is a false errand.
Look on the back of the panel. learn to understand what those terms mean. here is a simple how to.
https://www.altestore.com/blog/2016/04/how-do-i-read-specifications-of-my-solar-panel/#.X08dK8hKhPY
Now obtain a multimeter capable of reading DC Amps. Many cheaper meters will only read AC amps, which in this case is a meaningless number.
Test the VOC, this is the "open circuit voltage" this is NOT what you may receive under load, but it is what you need to know to compare to the back of the panel specs. that means put the red probe in the positive and the black in the negative. If you do not have an indication on the panel of which is which, you can pull the cover and look at the direction of the diodes, but you need to up your game on this stuff first. Lots of internet resources, most are confusing.
Do not kill yourself. DC can do the same damage as AC, most amateurs (like me) do not believe this until we make one mistake and if lucky we pick ourselves up, and feel sick for quite a while. A single 12 volt panel is unlikely to cause any issues. But if testing a full array, just pretend you are trying to catch a 6' rattler by the neck.
OK compare your full sun VOC readings to the spec. Remember all the " ratings" for ac and dc appliances are a range. 120 VAC can be 110-125 at any given moment. 12 VDC can be 11- 14 If in range move on to the ISC which is the dc amperage. Set the meter at DC amps in a range comparable with the spec on the panel, put the probes in the + and - and make a note. compare to the spec on the back.
All you have done, ( all you can do) is see if the panel produces what the manufacturer says it does. If you have bought a quality panel you have just wasted a bunch of time, because it will produce what it specs. If you did not, you have just wasted a bunch of money. Panels are freaking cheap now, go for the ones that offer LONG warranties and have been at it long enough you can expect them to be there 5 years on. Jeeze when I started I was paying over $700 for not much over a hundred watts. Now you can buy excellent quality for a buck or less per watt. Your real issues are the balance of system components.