Victron SmartSolar MPPT 250/70-Tr VE.Can rev2 limited to 35A?

[WorldwideDave]

I read somewhere - might be old literature - that the Victron SmartSolar MPPT 250/70-Tr VE.Can rev2 that I recently added to my setup is limited to 35A if used in a 12V environment, but 24/36/48V this is a non issue.

Anyone able to confirm this?

In VRM it *looks* like I did 66.4 A, but maybe that means the total current brought in from the panels but not put out by the panels?
Guess I need to figure out if Current (A) in VRM means what the panels did or what the MPPT output to 12V:

 

[ricardocello]

Output charging current for the MPPT 250/70-Tr VE.Can is 70A, as the name says, which is 840W at 12.0 V and more as the voltage increases.
The data sheet says to use 1000W nominal input power for the panels.

The PV input current is limited to 35A per the data sheet, meaning your total Isc of the panels should not exceed this if you are over paneling.
General consensus is that if you do exceed 35A of PV input current, nothing bad will happen unless you have the polarity backwards (so don't do that).

 

[ricardocello]

Guess I need to figure out if Current (A) in VRM means what the panels did or what the MPPT output to 12V:

In VRM Advanced Custom Widgets, "Current (A)" is MPPT output current to the battery.

"PV current" is the input current from the PV.

 

[WorldwideDave]

In VRM Advanced Custom Widgets, "Current (A)" is MPPT output current to the battery.

"PV current" is the input current from the PV.

Thanks - so is the limitation that I think (?) exists at 35 A on a 70A MPPT for 12V referring to the max amps on the input from PV, or the ouput to the battery (appears not in my screen shots)?

 

[WorldwideDave]

In VRM Advanced Custom Widgets, "Current (A)" is MPPT output current to the battery.

"PV current" is the input current from the PV.

along those same lines then, in VictronConnect, what is current referring to here, from PV or to Battery?



And please confirm that when I look at this, this is showing the following:
42.2A coming from 250/70 MPPT
38.30A coming from 150/100 MPPT
44.60 being used by my giandel inverter
36.20A is going through battery shunt to the battery.
Am I right?
Notice voltage difference between some of these. They are under 1' away from each other.
THANK YOU FOR RESPONDING!

 

[ricardocello]

Thanks - so is the limitation that I think (?) exists at 35 A on a 70A MPPT for 12V referring to the max amps on the input from PV, or the ouput to the battery (appears not in my screen shots)?

The limit is on the PV input current.

 

[ricardocello]

along those same lines then, in VictronConnect, what is current referring to here, from PV or to Battery?

Good question. Victron Connect is showing output current to the battery for "Current".
Probably because that is more useful information than PV current.

And please confirm that when I look at this, this is showing the following:
42.2A coming from 250/70 MPPT
38.30A coming from 150/100 MPPT

Yes, those are correct.

44.60 being used by my giandel inverter

Assuming the shunt is wired between the DC busbar and the inverter, that is correct.

36.20A is going through battery shunt to the battery.

That is correct.

Am I right?

Yes, you are.

Notice voltage difference between some of these. They are under 1' away from each other.

The largest voltage drop I see is 0.05 Volts to the battery.

Using V = IR to determine resistance, (0.05 V) = (36.2 A) (R),
so R = 1.4 milliohms (worst case). That's perfectly reasonable.

You are welcome.

 

[ricardocello]

So the currents should balance out, as current is never lost.
You have 42.2 and 38.3 coming in to the busbars, and 44.6 and 36.2 going out.

42.2 + 38.3 - 44.6 - 36.2 = -0.3 Close Enough
Keep in mind that that data isn't sampled instantaneously for these current measurements, so they will always be a little off.
Also, you may have other DC loads.

 

[WorldwideDave]

The limit is on the PV input current.
View attachment 284653

Looks like I hit around 70 on what I presume is the output current? Not sure. It was just shy of 1000W:

 

[WorldwideDave]

You are welcome.

You are a rockstar, thank you!

 

[WorldwideDave]

Output charging current for the MPPT 250/70-Tr VE.Can is 70A, as the name says, which is 840W at 12.0 V and more as the voltage increases.
The data sheet says to use 1000W nominal input power for the panels.

The PV input current is limited to 35A per the data sheet, meaning your total Isc of the panels should not exceed this if you are over paneling.
General consensus is that if you do exceed 35A of PV input current, nothing bad will happen unless you have the polarity backwards (so don't do that).

Well let's see...6 panels, 200W each, 1200W. Those are 8.5A each, so in series, stays at 8.5. But I have them in parallel with another string, so is that 2400W or 1200W when you parallel?

Think it stays 1200W. But you've pointed out 1000W max, and I was surprised to get close to that today. It is essentially 2400W of panels to get 1000W of power :-(

The voltage is way under 250 - maybe half - but the amps is maybe 20 max, so way under 35A on the PV input side. Am I right?

 

[WorldwideDave]

So the currents should balance out, as current is never lost.
You have 42.2 and 38.3 coming in to the busbars, and 44.6 and 36.2 going out.

42.2 + 38.3 - 44.6 - 36.2 = -0.3 Close Enough
Keep in mind that that data isn't sampled instantaneously for these current measurements, so they will always be a little off.
Also, you may have other DC loads.

yes the DC load is the inverter itself and the phantom/idle consumption loads from all the victron gear (read: low). Also when running a pump at 1500W, it takes about 1800W to do that due to efficiency of inverter or lack thereof (giandel is good, but not a victron).
The other problem with running a non-victron inverter, even with the shunt, is that in VRM and elsewhere -where you cannot customize the venus GUI v2 for example - I have things like A/C In and A/C Out just sitting there reporting nothing because it's going through the DC Load side.

 

[ricardocello]

Well let's see...6 panels, 200W each, 1200W. Those are 8.5A each, so in series, stays at 8.5. But I have them in parallel with another string, so is that 2400W or 1200W when you parallel?

You are wired as 6s2p.
Yeah, if you are using 12x 200W panels, you could get 2400 W at STC.
But no one gets that, it is usually less.

However, since your 250/70 is limited to 70A output, you wont see more than 1000W (at 12v).
What happens to the rest? Nothing, you are over paneled, and current limited.

You could probably get almost twice as power much if you had another 250/70.
Or, move up to a 24V battery.
On the other hand, if you don’t need more peak power, but want longer solar days, overpaneling as you’ve done is great.

Think it stays 1200W. But you've pointed out 1000W max, and I was surprised to get close to that today. It is essentially 2400W of panels to get 1000W of power :-(

See comment above.

The voltage is way under 250 - maybe half - but the amps is maybe 20 max, so way under 35A on the PV input side. Am I right?

yes, you are right.
You are nowhere near 35A of PV current, don’t worry about it.

 

[ricardocello]

yes the DC load is the inverter itself and the phantom/idle consumption loads from all the victron gear (read: low). Also when running a pump at 1500W, it takes about 1800W to do that due to efficiency of inverter or lack thereof (giandel is good, but not a victron).

That’s about 83%.
Victron inverters usually max out around 92%, but with smaller loads they can be in the 80s too.
No one tells you that.

The other problem with running a non-victron inverter, even with the shunt, is that in VRM and elsewhere -where you cannot customize the venus GUI v2 for example - I have things like A/C In and A/C Out just sitting there reporting nothing because it's going through the DC Load side.

Victron wants you to buy their inverters. They are not too keen in making it easy for competition in that area.
But at least you still get something in VRM.

 

[Brucey]

I read somewhere - might be old literature - that the Victron SmartSolar MPPT 250/70-Tr VE.Can rev2 that I recently added to my setup is limited to 35A if used in a 12V environment, but 24/36/48V this is a non issue.

Anyone able to confirm this?

In VRM it *looks* like I did 66.4 A, but maybe that means the total current brought in from the panels but not put out by the panels?
Guess I need to figure out if Current (A) in VRM means what the panels did or what the MPPT output to 12V:

View attachment 284648

In vrm widgets add all the available ones that will get you pv volts and amps and other graphs/data.

 

[WorldwideDave]

What happens to the rest? Nothing, you are over paneled, and current limited.

You could probably get almost twice as power much if you had another 250/70.

You are nowhere near 35A of PV current, don’t worry about it.

Well, I do have 9 more panels. I can maybe fit 4 more on my deck.

 

[WorldwideDave]

In vrm widgets add all the available ones that will get you pv volts and amps and other graphs/data.

At the bottom of the default view in VRM, you can show solar + consumption, or just solar. I'm looking to get that aggrigated "all PV W" in the 'advanced' page and cannot seem to find it.

 

[ricardocello]

At the bottom of the default view in VRM, you can show solar + consumption, or just solar. I'm looking to get that aggrigated "all PV W" in the 'advanced' page and cannot seem to find it.

I think you need a Cerbo for that. Total PV shows up under Gateway in VRM advanced.

 

[WorldwideDave]

I think you need a Cerbo for that. Total PV shows up under Gateway in VRM advanced.

Have cerbo...shows as gateway...total PV not listed.
Searching for total shows:



searching for PV shows:



Searching for (W) shows:



Searching for kWh shows:



lots of forecasting stuff and grid stuff, but not actual kWh listed.

 

[ricardocello]

Have cerbo...shows as gateway...total PV not listed.
Searching for total shows:.

Ok, don’t do a custom widget, look here and check the PV Yield:

 

[740GLE]

I think you need a Cerbo for that. Total PV shows up under Gateway in VRM advanced.

He has a cerbo

 

[ricardocello]

He has a cerbo

I should have realized that. He had VRM!

 

[WorldwideDave]

I should have realized that. He had VRM!

Thanks @740GLE for chiming in as well.

I have that:

but that is showing the combined performance of the array during the day for both of them charted by time of day - cool. But what I'm seeing is the total kWh produced, like this one at the bottom of the non-advanced, single day view:



The aggregate data - 9.8 kWh solar - and then I want to compare that number to other days.

See how in advanced you can see the aggregate number PER MPPT:





Imagine if you will a bar chart showing 9.8kWh today, 7.2kWh yesterday, etc based on day/time range, which you can sort of do here on the main dashboard (not advanced) by telling it a range (7 days), change it from 'system overview' to just 'solar' at the bottom?:


The problem comes when you want to do more than 30 days. Here is 30 days:



When last 90 days, instead of being like 30 days above, it aggregates each week, which I didn't ask for:



Furthermore, I didn't ask to see consumption at all - I just want the total, which you must hover over to see:


...which again I don't want to see direct use, and I don't want to hover and see a total for a week at a time, just a day, like the 30 day.
Pretty sure home automation software does or solar assistant or whatever. Thought this existed in cerbo gx land as well.

Here is the last 90 days with the PV Yeild:

Notice that it says only 1188 today, not accurate at all. Above you can see it hit 8x that today.

also, notice how if you have 30 days chosen, and you look at the charger summary, the charger summary doesn't have a yield total option, just today and yesterday. If it had something like average per day in range, or total in date range, or listed each of the 30 days total in a giant list that would be closer:



Bottom line is that if you have more than one MPPT, or just one, and you want to see 30, 90, 365 days plotted out, I can't find a way to do that. Something that simply displays the total amount yielded per day as tabular or bar chart data.

 

[ricardocello]

Notice that it says only 1188 today, not accurate at all. Above you can see it hit 8x that today.

You have to enable show peaks with “Show Range Values” using the little gear icon:

 

[WorldwideDave]

You have to enable show peaks with “Show Range Values” using the little gear icon:

View attachment 284784

getting closer. past 7 days. That is showing the range - high and low - better. But I just want to see the 'high' number.



With the 'show range values' off, is it showing the average then?

And again - I'm looking for the aggregate number, not the average, the high, or the low. Total PV produced, like at the bottom of the non-advanced dashboard:



Imagine if you will just a solid bar showing 9.87 solar for today. Yesterday would show its low 2.7. And back in time, just like that.
I don't need to see consumption at all. I don't need to see the sum of the daily values (38.1kWh for 7 days). What I need to see is basic bar charge with total number generated per day. That's it. From advanced. From a widget. Not sure it can, though that is why I bought the cerbo.