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Outback charge controller not using all of the arrays volts
#51
(06-05-2020, 01:24 AM)Doin it Wrote: Yes red I understand all of that.. the controller should still give me max volts (100vmp) if they are available and max amps (36imp).. for instance my controller will show 36amps at max when panels can supply 36amps,  but will not allow input from array voltage over the difference between 150v and battery voltage when controller is trying to draw max power from the array
Sorry but you don't seem to be understanding how your gear works or taking in what we're explaining.
I can't see anything wrong. Both the panels & the controller seem to be doing their jobs just fine.

Last attempt to help:
Do you have one of those non-contact laser pointer temperature meters?
If so can you please wait until late morning or middle of a sunny day & measure the cell temps of your panels.
Please also advise the ambient air temperature at the same time.
Please also take a pic of the screen of the FM60 at the same (ish) time while the controller is doing bulk charging.
Running off solar, DIY & electronics fan :-)
#52
(06-05-2020, 12:57 AM)Doin it Wrote:
On this graph it can be seen that the voltage cannot go over 150v combined depending on amperage of array..
Look at the circled part, 100v mppt from pv and 4438w max controller can produce.

Plus look at the graph again. What you circled shows you clearly what losses to expect when powering too high of what I assume to be Vmp, since I would assume the MPPT will track down to that point during maximum power of the panel. I just noticed the graph is of maximum power of the unit, not panel power but it shows higher output when your panels are closer to the battery voltage. It does correlate with efficiencies of the MPPT if powered too high of the voltage.

48V @ 70Vmp = 5022W
48V @ 90Vmp = 4847W
48V @ 100Vmp = 4672W
48V @ 110vmp = 4438W

You need to try and test different configurations. Trying to do other maths is hard.
#53
(06-05-2020, 05:54 AM)daromer Wrote: YES I have including many.

What is it that you dont understand ? The input side on for example Victron and PCM60x is isolated from the output. It is MAX 145VDC input on the input side and it will work fine above 115VDC. IF the VMP is 120Volt the PCM will stay at that IF the wattage is better than at 90V or whatever.

Same goes on my big unit...

MPPT is a system where it tracks the best power point and holds the input side at that voltage/current. Then it bucks it down to the battery side and thats why it need to be +2v Battery side.

The PCM is the most efficient at max 115Vdc. BUT it works fine up to 140VDC. And 140 + 60 = 200V combined. Way above...
So once again the issue you seem to have must be limited to that controller and design. It havent existed on any other controller i have installed. ALl other controllers have its input range defined as we have stated many times already. Input to be higher than battery but lower than max. And then the tracking point have its area where it works the best.

And then of course most controller have a MAX wattage they can convert.

I leave this thread now because it goes no where. Sorry.
I’m sorry to that I’m either this hard headed or I’m not explaining what I’m thinking properly. I understand that the input and output are isolated. But I also u understand that the controllers can only use voltages from array that are x amount higher than the battery voltage and still get all of the power from the array. For example in the pic when using a 24v battery and a 120v array the controller is only capable of 2353w.. this is because the controller isn’t capable of creating enough amps because it cannot use all of the 120v from the array because it can only boost the amps by so many and the 120v array has a lot less amps coming in than the 70v array..and also why if the array was only 70v and a 24v battery that 2700w can be supplied by the controller, because the controller doesn’t have to raise the amps so much and the controller is more capable of raising the amps to the max amps needed to get higher wattage..For instance if the array was 145v trying to charge the 24v battery the amount of power the controller can produce would be much lower than the 70v +24v battery could produce. And also with a 145v array charging a 24v battery that is over 150v combined by a good amount and the arrays full power could not be used because the input amps are to low for the controller to raise the amps enough to get full power from the array
When charging a battery that is the max battery the controller can charge (60v) what I just explained in the above paragraph still happens..but the difference is that 60v battery is at the top of the controllers capabilities to charge. Meaning that if my array was lower than 100v than I would have more amps coming in so the controller would not have to create as many amps to charge the same voltage battery,, and the lower than 100v array is more likely to get full power from the array because the controller doesn’t have to create as many amps because the array voltage is lower meaning theres more input amps.
As a battery goes from a 12v to 60v the difference between the arrays volts and the batteries volts must decrease,, or the controller ends up not being able to put out much power. And from what I’ve noticed the number is roughly 150v combined array + battery, this enables the controller to be able to use the amount of volts over the battery voltage, and then the amps the controller can create is within the capabilities of the controller and then full output from the array can be achieved
#54
Please ignore the voltage. You got that all wrong. There are No correlation between voltages. As Long as it is within limits you are. Med as Long as current or total wattage is below max.


When Power is limiting the voltage also goes Up towards voc
NOTE! My links supplied in this message may be affiliated with Ebay and by clicking on them you agree on the terms.
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 100kWh LiFePo4 | 20kWh 14s 18650 |  66*260W Poly | ABB S3 and S5 Trip breakers
Upcoming: 14S 18650~30kWh
#55
The FM60 is about 98% efficient from their specs here:
http://www.outbackpower.com/downloads/do...csheet.pdf

Look at this graph for the STC 290W version of your STC 305W panel:
(from the Longi spec pdf doc linked on page 2 of this thread)
 
You have to follow the red 800W curve.
Can you see on the right side of the hump to get the power up (vertical axis) you have to pull down the voltage towards the left from the max voltage Voc.
The voltage DOES NOT GO UP to get max POWER, the panel gets loaded & pulled down.

Note it says for cell temp = 25deg
Yours are out in the sun & are hotter. So the curves will be lower like this:


The way you're thinking about voltages is all wrong. 
If you keep down that path, you'll get nowhere & never understand how it actually works (yes for my & others systems too).
Physics (silicon & temperature) + electrical engineering are doing what they should in your system.
OffGridInTheCity likes this post
Running off solar, DIY & electronics fan :-)
#56
Redpacket showed your actuall issue. Look at that and as said ignore the voltage you look at. It doesnt work that way.
OffGridInTheCity likes this post
NOTE! My links supplied in this message may be affiliated with Ebay and by clicking on them you agree on the terms.
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 100kWh LiFePo4 | 20kWh 14s 18650 |  66*260W Poly | ABB S3 and S5 Trip breakers
Upcoming: 14S 18650~30kWh
#57
(06-05-2020, 12:23 PM)Redpacket Wrote: The FM60 is about 98% efficient from their specs here:
http://www.outbackpower.com/downloads/do...csheet.pdf

Look at this graph for the STC 290W version of your STC 305W panel:
(from the Longi spec pdf doc linked on page 2 of this thread)
 
You have to follow the red 800W curve.
Can you see on the right side of the hump to get the power up (vertical axis) you have to pull down the voltage towards the left from the max voltage Voc.
The voltage DOES NOT GO UP to get max POWER, the panel gets loaded & pulled down.

Note it says for cell temp = 25deg
Yours are out in the sun & are hotter. So the curves will be lower like this:


The way you're thinking about voltages is all wrong. 
If you keep down that path, you'll get nowhere & never understand how it actually works (yes for my & others systems too).
Physics (silicon & temperature) + electrical engineering are doing what they should in your system.
Yes I understand that the voltage I should get from array is not the voc but is the Vmp which is 33.3v for my panels x 3s = 99.9.. I’m not expecting voc from panels at max out put, but I am expecting within 300w of max for my array, due to heat loses etc

So if array Vmp is within 150v then all that voltage can be used to charge a 48v battery.. and the chargecontroller is supposed to be able to lower that many volts (150v) to 48v? To use all of the 150v the controller would have to convert all that voltage to ALOT of amps.. I’m not sure the max amps that the 150v controllers can convert from a given voltage but I don’t think they can convert that many volts to amps.. but if an the arrays Vmp is lets say 92v and charging a 48v= 150v battery than that amount of voltage can reasonably be converted to amps within the controllers capability.. I think I remember the max amps that the 150v controller can raise the array amps to charge battery is roughly 30amps for a 24v battery , something like 2/1 meaning for every 2 volts 1 amp can be converted, but with a higher voltage battery the controller only has a smaller amount of voltage over battery voltage to work with to create amps because the gap between battery voltage and array voltage is smaller with a 60v battery vs any lower voltage battery. . For a 60v battery the charge controller conversion ratio is only roughly 3/1instead of 2/1 for the 24v battery. The controller isn’t capable of creating as many amps when charging a 60v battery vs any lower battery voltage. I think charge controller (when charging a 60v battery) is only capable of converting like 12 amps (vs 30+ amps for a 24v battery) over array input amps so the charge controller can only allow in roughly 36volts over battery voltage (in my case 96v max, array Vmp + battery) because it can’t create anymore amps with the voltage any higher over the battery voltage. So for a person (using a 60v battery) to get close to max amps (60amps max) that the chargecontroller could produce, the arrays amps would have to be roughly 48amps because the controller can only create roughly 12 amps.. and if the array is 48amps then the arrays mppt voltage would have to be roughly 78 - 84v (not over or it’s wasted power) to not go over the 3750w max the controller can produce.. 84v + 65.1v battery = 149.1v
These are some reasons I’m thinking the 150v combined should be followed.
#58
m8 please ignore that voltage thing. you are guessing alot. Why not read what we have added as information to you please.

Why are you guessing about "Amps" it can convert? Why not read the specification? AND NO. The voltage above battery voltage is not such a thing. If you read what we have written like 10 times now you have the answer. The charge-controller will draw down the voltage to where the max power is pulled out. This is defined by the grafs supplied earlier. If the charger cant handle the power the voltage will instead raise instead and not the other way around as you suggest.

If you look around among people here you will see that there is no such thing as a combined voltage.
There are limits in the controller

Max power. Max voltage input. Preffered MPPT voltage range for the best efficiency. Min voltage above battery to work.

If you follow all those you will have ideal world. Stop mixing in imaginary rulesets.

The chargecontroller doesnt "create amps".. It doesnt convert voltage to amps either.

An mppt charge controller converts the voltage potential and by doing that with a good efficiency you change the current.

If you have 2kW of power at 120V. You will still have 2kW of power at 48V as long as the controller handle the current. Minus the efficiency losses of course.

As i said before I can easy have 120V input and producing max power from my panels going into my battery bank being at 56+V.

And if you read on your controllers specifications you will get your answer. First of all its max 60A output on the charge port.
On 48VDC systems its generally max 3kW and on nominal 60VDC its 3.75kW. So in your case you can potentially reach 3.6kW but this is a potentiall max.

If you read further it also says that it can take ALL voltages down to your desired battery voltage no matter what as long as its below 145VDC input.
And if you read further it also states peak conversion ratio. This is done at rather low voltage. its roughly 16v above battery voltage max.

With all those factors including the graf over your panel you have the answer and not your fictionary rules about combined voltage. THERE ARE NO SUCH thing since its an Buck converter. It doesnt combine voltages. It bucks down the voltage from the panels to the battery via a controller

And also. You codnt
Lastly. Start using newlines please.
NOTE! My links supplied in this message may be affiliated with Ebay and by clicking on them you agree on the terms.
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 100kWh LiFePo4 | 20kWh 14s 18650 |  66*260W Poly | ABB S3 and S5 Trip breakers
Upcoming: 14S 18650~30kWh
#59
Last post here... I’m not saying the controller combines voltages.. I’m merely saying that for the 60v nominal battery, the 60v battery voltage + array Vmp voltage combined should not exceed 150-160v to avoid loses (which I am seeing with 165.1v combined) due to the arrays input voltage being more than 30% higher than the battery voltage if the combined voltage is over 160v... 80v is what the controller optimally mppt at (for a 60v nominal battery) which is roughly 30% over 60v battery voltage and thats 80v + 60v=140v. For best efficiency I would want my array to be real close to that 80v, maybe 90v so that 150v combined. so anything over 150-160v (up to 160v due to battery voltage going up to 65.1v) combined for the 60v battery will start to have more and more of a power loss as the percentage goes over 30% higher than the battery voltage.. these are the losses I’m seeing, plus ofcourse basic loses from heat wiring controller efficiencys etc, these loses together make me have roughly 600w less than 3660w (Vmp x imp) from my array at max output..
I should have had a Vmp of closer to 86v maybe as high as 90v (I have 100vmp) to remove some of the losses from the 600w I’m not getting from my 3660w array. 90vmp + 65.1v battery= 155.1v..
Forgive me but I’m gonna throw another guess out there,,, a Vmp of 90v would have enabled me to have roughly 200 more watts. Because of efficiency losses when array start going over the optimal 30%.. so for every volt over the highest actual Vmp volt needed (roughly 10v to high in my case) I’m losing power and becoming more inefficient by every volt over the actual array Vmp volts needed..btw the numbers in the last post weren’t really guesses but more so trying to recall what I read somewhere over the years Wink for now I’m just going to deal with it till I build another house, then I’ll get 45ish Vmp panels and wire them 2s (90v) instead of 3s 33.3vmp panels (100v) like I have now, and then report back any improvements
#60
(06-06-2020, 01:26 AM)Doin it Wrote: Last post here... I’m not saying the controller combines voltages.. I’m merely saying that for the 60v nominal battery, the 60v battery voltage + array Vmp voltage combined should not exceed 150-160v to avoid loses (which I am seeing with 165.1v combined) due to the arrays input voltage being more than 30% higher than the battery voltage if the combined voltage is over 160v... 80v is what the controller optimally mppt at (for a 60v nominal battery) which is roughly 30% over 60v battery voltage and thats 80v + 60v=140v. For best efficiency I would want my array to be real close to that 80v, maybe 90v so that 150v combined. so anything over 150-160v (up to 160v due to battery voltage going up to 65.1v) combined for the 60v battery will start to have more and more of a power loss as the percentage goes over 30% higher than the battery voltage.. these are the losses I’m seeing, plus ofcourse basic loses from heat wiring controller efficiencys etc, these loses together make me have roughly 600w less than 3660w (Vmp x imp) from my array at max output..
I should have had a Vmp of closer to 86v maybe as high as 90v (I have 100vmp) to remove some of the losses from the 600w that I’m not getting from my 3660w array. 90vmp + 65.1v battery= 155.1v..
Forgive me but I’m gonna throw another guess out there,,, a Vmp of 90v (instead of 100vmp) would have enabled me to have roughly 200 more watts, because of efficiency losses when array start going over the optimal 30%.. so for every volt over the highest actual Vmp volt needed (roughly 10v to high in my case) I’m losing power and becoming more inefficient by every volt over the actual array Vmp volts needed..btw the numbers in the last post weren’t really guesses but more so trying to recall what I read somewhere over the years Wink for now I’m just going to deal with it till I build another house, then I’ll get 45ish Vmp panels and wire them 2s (90v) instead of 3s 33.3vmp panels (100v) like I have now, and then report back any improvements


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