how much pv on one controller?

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100kwh-hunter

100kwh-hunter

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I bought last week 14 "new" pv panels, good for ~3.5 kwh
I have a "spare" number 15, that is a bit stronger but is "the same"
14 "phono solar" and one i already had is the tri solar.
20230828_180058.jpg


20230828_180220.jpg

So i was thinking to put 3 of them on one mppt 100V20A
To get 92v max at 27A, now that is a bit to much?
Or 4 to get 61v at 18AI think i bought some wrong ones:(

The cheap mppt of victron is 100v at 20a,----> 148 euro.
a bit more expensive one would be the 150v 35A, ----> 343 euro
So yes my choice is the 100/20 or really go above 600 euro...:eek::mad:

What is the best way to connect those panels?
Cables are no problem btw.
14 * phono
1* trina

With kind regards Igor
 
The rule is to never go over the specified Voltage, the amps is no problem to go higher - aka. oversizing.

If we say that Voltage is someting the Solar panels 'GIVE' - Amps is something the charger 'TAKE' (less resistance more amps)

if you connect 3 of the Trina in Series, then you get 121,5 V (@25deg) - I learned that this can be higher on a cold sunny winter day....

I have tried different combinations but found that 3S (120V) is enough to charge my 70V battery. I also have some 40V Trina panels. I tried 2S (80V) but it's not high enough for the MPPT to do the job on a cloudy day.

My charger is can tage 230V - https://secondlifestorage.com/index.php?threads/solar-charger-rs485.12142/#post-86963
 
Here is a calulator from victron if you using there kit. mppt sizing.

You can enter you panel spec and it will work out a peak voltage for different temps which is worth watching out for colder it is the more voltage they make.

The reason to do more in series is to reduce solar cable current and take the solar voltage above mppt start voltage (battery voltage + abit)

For parallel as said above more is more power upto the mppt's max.

I went for a 150/35 for mine alows me to add more later and fitted 3 panles in series quite nicely.
Hope it helps,
Tom
 
Last edited:
www.renewablewise.com

MPPT Charge Controller Calculator: Find The Right Solar Charge Controller For Your System | RenewableWise

This MPPT calculator will determine the specifications of the MPPT charge controller that you need, provide links to MPPTs that match those specifications.
www.renewablewise.com www.renewablewise.com
I think this one is better than the victrons.
Victron will not allow me to put in higher pv than 24v and 270W

So just what i expected....2 parallel to get 82v and 1 serie to get 13a
So 7 mppt controlers?!?!?
I will pick "a fight" over witch controller, i will let you know the outcome.
If there is any hint, please let me know.
(finally i am getting out of the battery section and moving up:cool:)

With best regards Igor
 
I have 3,000W on a 500W controller. Most of these are shaded a great part of the day. The most I've ever seen on the controller is 240W. But, this allows me to operate for days with only a very minimum battery. When I do have excess, that goes to heat water from the array without impacting charge controller, inverter or battery. I run many things from the array without going thru a charge controller like a clothes washer, it even has its own tank and all cycles are done with hot water. Even have a dishwasher which many think is impossible with a small system. I operate things when the sun shines and that allows me to get away with nothing for a battery. You don't need a bigger or more charge controllers. The best use is an east facing panel. Face them different directions to get consistent power all day.
 
Norknid thats a ratio and a half not sure I've heard that many panels on one mppt! How do you connect them together? Do you fuse each parallel string?
 
Say you have 9 panels, then you can make 3 strings - each string will be about 120V / 9.46A (1135W)
You can now parallel the 3 strings and still get 120V - but 3x8.85A = 28.38A (3405W)
In this case each string must be fused because the total amps is above the max. fuse of the panels.
 
100kwh-hunter said:
I am curios also.
Click to expand...
This is the one minute tour of laundry with its own hot water tank running from PV at my camp (five months summer). For three years I did laundry with no battery, PV going right to inverter. his year between soke from Canada and constant clouds a batty had to be added. Not a big one, on from town recycling with about 10AH. It only supplies power when needed, about 150W. That is blended with PV.
View: https://www.youtube.com/shorts/pEIiw2AvTeQ


Shop uses this 60V inverter. It automatically turns on and off. Whole house runs on just a car battery. And I have a dishwasher. Hot water from excess PV my specialty.
GarShops.jpg
 
LOVE IT!
but where you are located, is unfortunaly not were i am located.
And when we are at work the sun does shine, when we are at home it is evening.

With best regards Igor
 
100kwh-hunter said:
The cheap mppt of victron is 100v at 20a,----> 148 euro.
a bit more expensive one would be the 150v 35A, ----> 343 euro
Click to expand...
You will get better value with the 150v35A one. With that one you can do 3 panels in series and shouldn't overvoltage as long as you don't get really below freezing temperatures(I have a similar setup and had to upgrade to the very expensive 250v options because I do get very cold -20 temps and it would put my charge controller into safety mode). You can then have 4 parallel sets of 3 with full utilization or do all 15 as 5 parallel sets and then you would be somewhat over the max input amps(5*8=40ish) but that will just mean you are at max production more of the day/during shade. One other thing to check though is the output limits of the mppt which are usually only found once you dig into the datasheet because if you are maxing out the input side the limiting factor can be the output amp capability particularly if you are doing a 12/24vdc system vs 48vdc. At max production you would be producing about 3kw which is a lot of amps in 24vdc(more than 100A) and often mppts can only actually charge at the advertised kw rate with batteries at the highest voltage they are designed for.
 
cak said:
heck though is the output limits of the mppt which are usually only found once you dig into the datasheet
Click to expand...
From experience i can tell(maybe i had it wrong!) what is printed on the mppt is the max output.
From what i can remember i had a cold sunny day and i thought the input was around 1000watts at 92v, but my bms told me that there was 2kwh coming in at 48vdc.
Funny how those things work, again i could be very wrong in the ?interpretant?(google spelcheck) of the reading.

With kind regards Igor
 
norknid said:
his is the one minute tour of laundry with its own hot water tank running from PV at my camp (five months summer). For three years I did laundry with no battery, PV going right to inverter. his year between soke from Canada and constant clouds a batty had to be added. Not a big one, on from town recycling with about 10AH. It only supplies power when needed, about 150W. That is blended with PV.
Click to expand...
a lot of more interesting vids are showing up!
Good channel.
 
100kwh-hunter said:
From experience i can tell(maybe i had it wrong!) what is printed on the mppt is the max output.
Click to expand...
I was very very v e r y wrong.
cak said:
One other thing to check though is the output limits of the mppt which are usually only found once you dig into the datasheet
Click to expand...
You were very right.

The numbers printed on the casing are the max input voltage and amperage, max.
What they can charge max at 48v:
The 150/35 can charge max 2kw
The 150/45 can charge max 2.6kw

I think i will buy one of each?

there are now 3 sets of pv on the roof, for the other two i need to extend the shed.

One panel is 35v and 8.5a 260wattpiek.
Every set is 35v+35v+35v=135v at 8.5A = 1.1kw
Times 5 sets is 5.5kw!!!

So i think it is clever to put 3 sets on the (max input) 150/45 (max output 2.6kw)
And two sets on the 150/35 (max output 2kw)

With the first three sets, one set is facing southwest, and the other two sets are facing east south.

What do you all think?

With best regards Igor
 
For the ones that are interested:
model​
max output​
Price 2023​
Price 2024​
​
100/20​
1160w​
148​
89,66​
​
150/35​
2000w​
343​
205,76​
​
150/45​
2600w​
480​
247,14​
​
150/60-tr​
2600w​
​
390,83​
faster/more ai​
150/70-tr​
2600w​
​
431,06​
faster/more ai​
150/70-mc4​
2600w​
​
431,06​
​
150/100-tr VE.can​
4000w​
​
610​
faster/more ai​
250/70-tr ve.can​
4000w​
​
610​
faster/more ai​
250/100-tr VE.can​
4000w​
​
​
​
​
​
​
​
​
​
​
​
​
​

Prices are in euro and for victrons mppt's

Above 4kw prices will go beyond 1000 euro and quickly up to 5k.
Only for mppt's that is.

So i will stick to the "normal" no AI or tr just the blue solarsssssss and configure my pv according to that.
Funny how much you can learn over here....just some simple comments, just some pointers...

Thank you all for everything!!!!all of you, thanks that i can tribute finally myself some valuable stuff.

Inputs are printed on the casing/outer shell, dont cross those values. nieter in V or A.
Or the mppt will damage itself with to much V or it will go into safe mode thru A and wont charge thus shuts down.
That is the input! for the max output look at the table i made.


With best regards Igor K
 
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