Real world output of 2 100 watt renogy solar panels

[nomadweb.design]

Hello, I have 2 X 100 watt Renogy solar panels that I am planning to mount to the top of my Promaster Van. Before mounting everything I am testing the equipment to make sure everything is working properly.

My setup
2 x 100 watt Renogy Solar panel *wired in parallel
100AH AGM weize battery
20a Renogy MMPT PG series charge controller
15 & 20 amp Fuses
10 AWG wire, branch connectors, all renogy parts

I just got the battery and it came charged, I also put the battery tender on it to top it off at 100%. Upon connecting it to the Rengoy MMPT it showed 100%.

It seems like when the battery is 100% and no load is on the system, the AMPs coming from the panels is dropped pretty low like around .25.

I tested putting a small fan on and the AMP input from the panels went to around 4.5amp. The panels are outside leaning on the van pointed at the sun and I would say it's not 100% ideal conditions but not bad. It is chilly out and it's early in the day.

I made a quick video showing the setup and the readings on the MMPT. You can see at the end of the video I turn off the Fan Load and the amps drop.
https://andrewmabry.com/solar.mp4

Just want to know if this seems normal and if I can proceed to mounting on the roof.

Thanks so much!!!

 

[Ped]

Thats normal. 100w - 10A average...if the battery will accept it.

Im gonna warn you if your using that full time and pulling below 30-40% thats not enough solar for that battery.

 

[nomadweb.design]

The battery will not get full time use and the only loads on it are pretty minimal (less than 100 watts for a few hours). Battery will never go below 50% or even 75%. Van will be sitting for days in the sun with no use on battery, all the while charging.

 

[Ped]

Ok good

 

[Deleted member 783]

Disregard the percentage charge, particularly on Renogy. It will say 100% from about 13.5 volts up to fully charged. It's better to get used to using voltage rather than percent. Also, I suggest checking your charge paramaters. Renogy has some very inappropriate numbers for charging, particularly for the charge limit. Mine were set at 15.5 from the factory, while 14.2 is correct, which was slowly cooking my batteries. I can't watch the video at the moment but as soon as I do I'll reply if I can be helpful. I can tell you that I have seen 392 watts from my 4 renogy mono panels, at their peak.

 

[nomadweb.design]

Ok, just went out and put 2 fans on to create heavier load, also readjusted panels and saw the amps go up to about 6.7. I looks like the MMPT adjusts the amp input from the panels depending on the load and the battery state. This is starting to seem more accurate.

Question now is, a single 100 watt panel could not produce 6.7amps? Just want to make sure in fact both my panels are producing power and from my tests so far it appears they are. Thanks for the input!

 

[Ped]

Disregard the percentage charge, particularly on Renogy. It will say 100% from about 13.5 volts up to fully charged. It's better to get used to using voltage rather than percent. Also, I suggest checking your charge paramaters. Renogy has some very inappropriate numbers for charging, particularly for the charge limit. Mine were set at 15.5 from the factory, while 14.2 is correct, which was slowly cooking my batteries. I can't watch the video at the moment but as soon as I do I'll reply if I can be helpful. I can tell you that I have seen 392 watts from my 4 renogy mono panels, at their peak.

Fyi - the renogy is set at 14.2v bulk for gel. 15.5v was max voltage cutoff and the reason for it and the reason it went over 14.2v is 1. Equalization, and 2. Temp compensation. The colder it is the higher the charge voltage needed.

His AGM needs temp compensation to charge property. He will need to turn equalization off and use it only if he notices a capacity loss. Probably about 2x a year after the first 6-12 months.

I recommend an aili battery monitor if you want one.

Amazon.com: AiLi Battery Monitor Voltmeter Ammeter Voltage Current Meter 8-80V 0-100A Auto Car Motor Boat Caravan RV Motorhome: Home Audio & Theater

Buy AiLi Battery Monitor Voltmeter Ammeter Voltage Current Meter 8-80V 0-100A Auto Car Motor Boat Caravan RV Motorhome: Battery Testers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[Deleted member 783]

Ok, just went out and put 2 fans on to create heavier load, also readjusted panels and saw the amps go up to about 6.7. I looks like the MMPT adjusts the amp input from the panels depending on the load and the battery state. This is starting to seem more accurate.

Question now is, a single 100 watt panel could not produce 6.7amps? Just want to make sure in fact both my panels are producing power and from my tests so far it appears they are. Thanks for the input!

I believe the amp rating on those panels is 5.96. Going off memory.

 

[nomadweb.design]

So does this seem like my system is running as it should? These are all brand new parts (panels, battery, mmpt, cables, connectors etc)

 

[Ped]

Yes

 

[Deleted member 783]

So does this seem like my system is running as it should? These are all brand new parts (panels, battery, mmpt, cables, connectors etc)

Yes, it does. Your panels are wired in parallel, yes? COOL VAN

 

[nomadweb.design]

Yes in parallel, thanks Will love your stuff man ??

 

[Deleted member 783]

Yes in parallel, thanks Will love your stuff man ??

Wrong Will but thanks! ? You're good man-enjoy the power!

 

[Ped]

Lol

 

[nomadweb.design]

21 volts and 6.7 amps = 140 watts, thats what I saw peak today, so from what I've researched a Renogy 100 watt panel in optimal coniftions puts out 70-80 watts and my tests would fall into that category. I guess I was suprised at how high the voltage was (21) and how low the amperage was (6.7), being that these are wired in parallel. I was expecting 14-15 volts & 8-9 amps.

 

[Ped]

Cause theyre pointed. Itll get worse when you mount them. Prolly see like 17v @ 140w

 

[nomadweb.design]

I've also got a 100w panel that I throw out when parked/camping and planning to mount another 50w to run a fantastic vent/fan. Everything I run has been selected based on low wattage, TV 20 watts, led battery lights, Ryzen 3400g pc 55 watts, 22" Asus monitor 18 watts, tiny stereo 3 watts. Coffee is pre-ground and using a butane stove to heat water. I dont camp where it's hot. Mr Buddy propane heater for extreme cold. 4 blankets and thermals, 2 dogs and a cat, Happy Camper!

 

[Ped]

Cool im a vanner too.

 

[nomadweb.design]

So today it was pretty overcast, now my panels are mounted to the roof, I saw peak of 4 amps and 19/20 volts. I also put a load of 19" TV, PC stick, 22" Asus computer monitor, cheap chinese stereo amp (w/ smooth jazz) & small Fan, watt meter peaked at 80 watts, so looks like even in decent conditions I was producing more energy than I was using. After turning everything off battery pretty quickly went back to float 100%. Now at night saying 90%, guess that's normal with no solar.

 

[Ped]

Hey you dont want to float. Turn that up to 14.4v and make the controller into 2 stage. It goes to float based on a timer not when it really needs to. Which is when amps taper below 1-3% of banks AH's. Lot of battery manufactures are realizing this is a big cause of premature failure.