Parallel or series?????

dcwettstein

Well-known member
I have 4 Uni-Solar PVL-136 panels on the roof of my 5er. at full sun my Tristar Digital Meter reads 46 volts. I have the panels hooked to a MPPT controller in parallel. would I be better off having 2 sets of panels hooked in series to increase the voltage?
 

Brazos

Active Member
dcwettstein,
My first question to you would be are your panels performing well now and charging your batteries? It is not always the best practice to throw more voltage at the charge controller. The MPPT charge controller is most efficient at 35 to 40 volts. If you have the 45 or the 60 Tristar they would handle the increased voltage. I am sure you realize when you monitor your charging you see you get the max output from them in full sun. Sometimes the varying output we monitor during the day plays head games with us and we start to question. I looked up the specs for your panels and if I was looking at the right specs it looked to me like you were right on with your voltage with min. voltage drop.
Perhaps others will come along with a better handle on stick down panels that can give you a more qualified answer than any answer I would have. I think Jim Allison could give you good input since he has a similar system. One of my friends has panels like you have and he went through a serious hail storm. He received real serious hailstone dents in his panels from the hail and he states the dents don't seem to affect the panel performance. That should speak well for them.
 

Imurphy

Member
The biggest issue with having RV panels in series. Is shading, if you shade 1 panel it pulls down the whole system. While if each panel is independent, you just loose the production of the panel and the rest keep on cooking. I would not change what you have now.
 

carl.swoyer

Well-known member
I use morningstar sun saver duo and 1 220 watt panel. The duo controller allowed me to send charge to 4 group31 deka batteries and two heavy duty wet cell batteries. The controller splits the charge 90/10% or 50/50 split while charging at the correct rate for each battery bank. My grp 31 batteries are my dry camp. And the wet cells are my house batteries. Also changed all my lights to led. At night we turn the frig off to save on batteries.

Sent from my XT1254 using Tapatalk
 
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