Question on Reduced Capacity
- Thread starter gabe1475
- Start date
Are you connecting in series or parallel? Are they flexible or rigid panels?
What are the Vmp and Imp ratings of each panel? They may be different if they were purchased at different times.
PWM or MPPT?
How are you testing the output?
What are the Vmp and Imp ratings of each panel? They may be different if they were purchased at different times.
PWM or MPPT?
How are you testing the output?
Ampster
Renewable Energy Hobbyist
Perhaps it is what you are plugging them both into. Does "it" have a limit of 130 Watts? Is "it" a charge controller or other device. On the surface from what you are saying, the panels seem to be performing.
It the SCC showing it's in bulk charge mode?
both are 17.7 VMP and 5.7 IMP, though, per renogy's specs, but I can not look at the back of the panels as they are mounted. I will add they were purchased within 4 months of one another.
OK, those would be 100W (17.7 * 5.7) panels, not 160W. That makes more sense if each is giving you 90-100W.
Try the panels in series and see what you get. It could be something with your Y-connectors.
at the time I started writing it was 10:30 so not best condition, also flat mounted so best I can get is 130 or so in the middle of summer. Was just going to ask about wiring in series.
Wired in series and jumped to 230. At the same time noticed that my charger had switched to Absorption charging from bulk. could that cause the cap at 130W?
The max power the SCC puts out is in bulk mode. Absorption tapers the current down as the battery becomes fully charged so it's not a good way to measure your panel capacity. The SCC will only put out what the battery will take.
Went back and checked and got some better numbers on parallel wiring, but still a significant difference to me. 230 W in Series and 200 in Parallel. Is that considered normal?
Are you 100% positive both of the panels have the same Vmp and Imp? The numbers you previously gave are for a 100W panel.
100W + 100W only means 200W if the panels are 100% the same ratings. If they are different, you may be seeing that in your results.
100W + 100W only means 200W if the panels are 100% the same ratings. If they are different, you may be seeing that in your results.
Not 100% sure they are identical, just per the specs from Renogy. both are 160W , just producing lower due to being flat mounted. Was thinking that both parallel and series are limited by either Volts or Amps respectively and assuming any difference should more or less be the same. They are mounted sloping in opposing directions since the roof has a slight arch and they are side by side, that could probably cause a difference as well.
When hooking up individually Volts were fairly similar on both as shown by the charge controller, that is why I was thinking results should be closer than they are.
Those numbers don't add up. 17.7 Volts times 5.7 Amps = 100 Watts, not 160 Watts.
Yes, indeed.
Got it. Yes I pulled the wrong information 20.2 and 7.92 should be it.
Actually had some time to think about this and wanted to see if anyone had input.
Wiring my two panels in series results in 230 as the highest wattage for the day, while parallel leads to 200. My first thought was to wire in parallel since the panel on one side would not be compromised if shading on the other panel came into play. Then I started thinking that the time that this would happen may be minimal and offset by the better performance when shading is not a factor since the panels are installed less then one foot from one another. Anyone thoughts on this?
Wiring my two panels in series results in 230 as the highest wattage for the day, while parallel leads to 200. My first thought was to wire in parallel since the panel on one side would not be compromised if shading on the other panel came into play. Then I started thinking that the time that this would happen may be minimal and offset by the better performance when shading is not a factor since the panels are installed less then one foot from one another. Anyone thoughts on this?
I went series. The way I camp, I figure if one panel is shaded, so is the other one. Series wiring is easier and less expensive.
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