Solar Panel Output

bte52 · 04-12-14, 11:44 AM

I purchased a 100W (2*50W) 12V folding mono solar panel with 15A solar charge controller from eco-worthy. They just arrived so I wanted to test them using a multimeter. I disconnected all the wires from the charge controller so that I could test each one independently. I tested in bright sunlight at high noon here on the East Coast. The stickers on each panel say the VOC is 22.41V and the ISC is 6.2 amp. One panel read 22.14V and the other 22.12V but noticed they started to drop a few volts rather quickly. My main concern is the fact that the ISC on both was lower than the rating (one was 3.12 amps and the other was 2.89. Do I have a problem here that I need to address with the mfg? Any help would be much appreciated.

NiHaoMike · 04-12-14, 11:47 AM

The output is measured under ideal conditions and in practice, can be expected to be much lower.

OffGridKindaGuy · 04-12-14, 02:18 PM

Take your total wattage and divide by 17.. 100 divided by 17 = 5.88 amps. Your readings.. 3.12 + 2.89 = 6.01 amps. I'd say that you're doing OK..

I use 17 as a divisor for real world calculations because nothing is perfect and the sum is more realistic.. (Including burn-in)

New panels are always hotter than normal. (higher in output) After being used for a while, the output will drop a little and stabilize..

bte52 · 04-12-14, 02:57 PM

I appreciate your help very much. I am still a little confused though. If each 50W panel has an ISC of 6.2 amps and I tested them separately why do we add both panels together? Sorry for stupid newbie question.

04-12-14, 11:44 AM	#1
bte52 Lurking Renovator Join Date: Apr 2014 Location: Salisbury, MD 21804 Posts: 6 Thanks: 5 Thanked 0 Times in 0 Posts	Solar Panel Output I purchased a 100W (2*50W) 12V folding mono solar panel with 15A solar charge controller from eco-worthy. They just arrived so I wanted to test them using a multimeter. I disconnected all the wires from the charge controller so that I could test each one independently. I tested in bright sunlight at high noon here on the East Coast. The stickers on each panel say the VOC is 22.41V and the ISC is 6.2 amp. One panel read 22.14V and the other 22.12V but noticed they started to drop a few volts rather quickly. My main concern is the fact that the ISC on both was lower than the rating (one was 3.12 amps and the other was 2.89. Do I have a problem here that I need to address with the mfg? Any help would be much appreciated.

04-12-14, 11:47 AM	#2
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,152 Thanks: 14 Thanked 256 Times in 240 Posts	The output is measured under ideal conditions and in practice, can be expected to be much lower. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

04-12-14, 02:18 PM	#3
OffGridKindaGuy Hi-Tech Hillbilly Join Date: Mar 2010 Location: Ohio Posts: 97 Thanks: 1 Thanked 16 Times in 15 Posts	Take your total wattage and divide by 17.. 100 divided by 17 = 5.88 amps. Your readings.. 3.12 + 2.89 = 6.01 amps. I'd say that you're doing OK.. I use 17 as a divisor for real world calculations because nothing is perfect and the sum is more realistic.. (Including burn-in) New panels are always hotter than normal. (higher in output) After being used for a while, the output will drop a little and stabilize.. __________________ If it don't, I'll always think it shoulda..

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

04-12-14, 02:57 PM	#4
bte52 Lurking Renovator Join Date: Apr 2014 Location: Salisbury, MD 21804 Posts: 6 Thanks: 5 Thanked 0 Times in 0 Posts	I appreciate your help very much. I am still a little confused though. If each 50W panel has an ISC of 6.2 amps and I tested them separately why do we add both panels together? Sorry for stupid newbie question.