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Its wrong...just wrong. Read what we have explained. There is No such thing as combined voltage.
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Ik there isn’t such a thing in the manual etc.. that doesn’t mean it doesn’t exist.. it can’t be denied the the optimal array vmp for the highest voltage battery (60v) is 90v and that happens to equal 150v... this combined voltage is the most efficient voltage for a 60v battery,,, an array over 90v is not as efficient and unnecessary losses would happen.. the 60v battery is the highest the outback can charge, so an array Vmp for any other lower volt battery should be lower than the optimalmost efficient array (90v) that the 60v battery should use.. therefor 150v should be the highest combined voltage for any battery lower than 60v.. this is true because the further the array voltage is from the battery voltage the less efficient the controller becomes.. the optimalmost efficient mpp voltage for the 48v battery is 68v right? That’s what the graphs says... so that combined is 116v and 10 more volt higher Vmp to make sure mpp is reached = roughly 126v combined voltage for the 48v battery for optimal efficiency,, the graph shows any higher array voltage used will be less efficient.............
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No and no.
Start to use "Enter"
The controller you have do have that YES but it have nothing to do with the 150V. Thats the max input voltage limit and nothing else.
What you have done so far is just to twist the numbers to suit something you made up. Instead look at facts.
A manufacturer of a charge controller (If they know what they are doing) will optimize the charger to a certain setup. That often fits the most common setup out there like 3s with 60c or 72c panels.
So stop referring to that the efficiency is in direct relation to 150v number because it isnt. Its just a coincidence for that inverter.
And once again go back and read what we all have tried to explain and you will see that we dont object efficiency or what not. Its the relation to the max voltage input that is bogus.
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06082020, 10:31 PM
(This post was last modified: 06082020, 10:37 PM by Doin it. Edited 3 times in total.)
How is is bogus.. I didn’t make it up.. math is what math is...I’d strongly assume this is the same for every 150v inverter, the further u get from the battery voltage the less efficient the controller becomes. Read the graphs it shows this..
also do u see in the one pic where it says the optimal mpp voltage for particular battery voltages. U can see in the pic I posted and the graph red and I both posted how the optimalmost efficient mppt voltage for batteries is lower if the voltage of the battery is lower.. 60v battery has a higher optimal mpp voltage than a 48v battery, this is shown on the graphs..
for a 60v battery pic says 80v mpp voltage is the optimal input voltage., to make sure thats able to be achieved a 90vmp array should be used= 60v +90v=150v..
At this point I give up.. good luck to yas, and if u want to have an array over the optimal most efficient array voltage for your battery that’s fine with me.. read the graphs and see what your optimalmost efficient voltage is for your battery,, then add that to your battery voltage,, I bet it’s under 155v and I bet for a 48v battery the combined voltage would be under 130v...
I will not post again on this issue.. no matter what is said
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To all boys and girls joining this class
(06082020, 10:31 PM)Doin it Wrote: for a 60v battery pic says 80v mpp voltage is the optimal input voltage.,
This statement is correct. To have optimal voltage it tends to be 1020 volts higher. Your panels needs to have a higher voltage than the battery to be able to charge it. That's it.
(06082020, 10:31 PM)Doin it Wrote: to make sure thats able to be achieved a 90vmp array should be used= 60v +90v=150v..
This statement is utter nonsense. It's a number made up that seems to coincide with something utterly unrelated. Please do not even try to make sense of it. It will just drive you nuts!
Here's one that's better, I lived on a street when I was a kid and the address was 600 Den Cove. It was a red apartment building with 6 floors and 60 apartments. It always creeped me out. Then one day I started looking at the numbers and added it up, 600+6+60 = 666! It was the mark of the devil! True story!
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06092020, 12:11 AM
(This post was last modified: 06092020, 04:27 AM by Redpacket. Edited 1 time in total.
Edit Reason: out by a decimal point
)
You've come up with an imaginary number addition. Yes, you made it up.
It's not engineering based & is nonsense. No system designers use it. The manufacturers don't use it.
Sooner you give up on that the better for your understanding & our sanity.
I'm pleased to see you've realized that higher voltage doesn't mean more power & the best efficiency point is Varray approx 20V higher than the battery voltage. This is progress.
When your panels are new they may produce up to +5W according to the spec.
When your panels are cold &/or there's a good wind blowing you may also get a bit more than the NOCT numbers.
If you post a screen shot of the FM60 & tell us the temperatures of your panels at peak production we can tell you why you're getting the claimed 350W more than ~2,690W NOCT value expected.
We can use the manufacturers spec of "temperature coefficient of Pmax = 0.410% per deg C from STC (25C)"
So for your 224.2W NOCT panels, that's 224.2 x 0.0041 = ~9.2W per panel per deg C away (lower) from 44 degC typical NOCT < edit, oops, wrong number fixed
That's 0.92W x 12 panels for your array, ie 11W more per degC lower than NOCT temp. < edit, oops, wrong number fixed
You may also get up to 60W of variance from the = +5W/panel in the spec.
So basically if your panels are 30 degC below NOCT, you'll get the +350W you're seeing. < edit, oops, wrong number fixed
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06092020, 02:00 AM
(This post was last modified: 06092020, 03:02 AM by Doin it. Edited 12 times in total.)
I guess I can’t resist... 90v is not a made up number.. 80v is 30% higher than the 60v battery, string sizing tools recommend an array with a 30% higher voltage than the battery voltage so the battery can be charged and so the optimal voltage to charge the battery can be achieved, that will make your controller operate the most efficient.. that equals 140v.. the graphs show that if the installed array was higher in voltage the efficiency goes down..
I added 10v to the 80v to assure the optimal 80v can be achieved from the array so that makes a 150v combined voltage.. 140v combined would be more efficient due to the array being 10v lower, graph shows if installed array had lower Vmp input then controller would be more efficient.. problem with combined 140v is that then the array is only 80vmp so I added the 10v to assure that 80v (optimal most efficient voltage shown on graph) can be achieved..
so since my numbers are socalled nonsense.. answer this for me.. What is the most efficient array voltage for a 60v battery, and same question for 48v battery..
going by the graphs thats 68v for a 48v battery= 116v
Going by the graphs that’s 80v for a 60v battery=140v
most efficient combined voltage for the highest battery the controller can charge is 140v150v....engineers etc do use this number even if they don’t know it because that’s the most efficient combined voltage for the highest battery voltage their controllers can charge... or would a combined voltage for the 60v battery be more efficient at 170v,, Ik the answer,, it’s no, it wouldn’t be more efficient because the graphs show that if the arrays mpp voltage is higher that there is less efficiency.. 170v is higher than 150v...
I could just be saying that the most efficient array voltages are blank for each battery but then the battery voltage would have to be said and the array Vmp would have to be said separately, so if it makes yas happy even tho it’s a longer way to look at it  type it... 48v batteriesarray should be roughly 68v for best efficiency...
60v battery 80v array should be used for best efficiency.. add them together if u want
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(06092020, 02:00 AM)Doin it Wrote: ....
the battery voltage would have to be said and the array Vmp would have to be said separately, ....
48v batteriesarray should be roughly 68v for best efficiency...
60v battery (then) 80v array should be used for best efficiency.. now you're talking, yes, that's right
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The combined Number of 150 is nonsense. Its max input 150. Where the max efficienct is have nothing to so with 150... That it is at same place is something else.
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(06082020, 09:10 PM)Doin it Wrote: Ik there isn’t such a thing in the manual etc.. that doesn’t mean it doesn’t exist.. it can’t be denied the the optimal array vmp for the highest voltage battery (60v) is 90v and that happens to equal 150v... this combined voltage is the most efficient voltage for a 60v battery,,, an array over 90v is not as efficient and unnecessary losses would happen.. the 60v battery is the highest the outback can charge, so an array Vmp for any other lower volt battery should be lower than the optimalmost efficient array (90v) that the 60v battery should use.. therefor 150v should be the highest combined voltage for any battery lower than 60v.. this is true because the further the array voltage is from the battery voltage the less efficient the controller becomes.. the optimalmost efficient mpp voltage for the 48v battery is 68v right? That’s what the graphs says... so that combined is 116v and 10 more volt higher Vmp to make sure mpp is reached = roughly 126v combined voltage for the 48v battery for optimal efficiency,, the graph shows any higher array voltage used will be less efficient.............
This thread is a lot easier to understand after a few drinks!
So just to clarify, Your array + battery should equal 150 because that is the max OCV for the controller that happens to fit the efficiency curve but if you had a 48v battery then the numbers are totally random and don't fit your coincidence math? Is the 48v battery 48v nominal or Max? Is your 60v battery nominal or max? I have so many questions and at this point I'm just stirring the pot.
If you keep smashing your head into the wall and it isn't busting a hole is that because your head is soft or the wall is really hard?
