Victron MPPT over panelling

[Urge38]

By how much can you over panel a Victron 100/20

the data sheet just says the MPPT will deal with it !!!

a) If more PV power is connected, the controller will limit input power.1b) The PV voltage must exceed Vbat + 5 V for the controller to start. Thereafter the minimum PV voltage is Vbat + 1 V2) A PV array with a higher short circuit current may damage the controller

On my Tri Star, it states 130% of Nominal Max Ouput Power

 

[timselectric]

You have to be careful with Victron SCC's.
They aren't like other MPPT's.
Part of their sweep includes shorting the circuit.
They are very limited with overpaneling.

 

[ScrotusGobbleBottom]

You have to be careful with Victron SCC's.
They aren't like other MPPT's.
Part of their sweep includes shorting the circuit.
They are very limited with overpaneling.

YES, I can see this shorting of the circuit on my graphs.

 

[fega72]

You have to be careful with Victron SCC's.
They aren't like other MPPT's.
Part of their sweep includes shorting the circuit.
They are very limited with overpaneling.

You can over panel Victron solar charge controllers, it will limit the charging current to the max designed amps or you can lower the charging amps in the settings. My two 100/30 connected to 1200W solar panels each, the 100/50 connected to 1620W solar panels. No problem at all. Running like that nearly 3 years.

 

[fega72]

YES, I can see this shorting of the circuit on my graphs.

I can not see any of this on the vrm

 

[Rocketman]

I have 600w going into a Victron 100/30 (max output of 420watts) works fine except the mppt gets very warm (almost hot).

 

[DVD]

You have to be careful with Victron SCC's.
They aren't like other MPPT's.
Part of their sweep includes shorting the circuit.
They are very limited with overpaneling.

That has not been my experience. Serious over paneling (300%) doesn’t seem to bother the ones I’ve used.

 

[ScrotusGobbleBottom]

I can not see any of this on the vrm

It doesnt show up on VRM. If you connect to your SCC via bluetooth you will see it. Every 10 minutes or so it goes to 0 output for 2 seconds.

 

[sunshine_eggo]

You have to be careful with Victron SCC's.
They aren't like other MPPT's.
Part of their sweep includes shorting the circuit.
They are very limited with overpaneling.

HUH? You know I hate to argue with you, but I think we disagree here...

They publish two rules, both values are published in the MPPT datasheets:

Array must never exceed Voc (100V in this case) even in cold conditions.
Array short circuit current, Isc, should not exceed PV input current limit.

I post this so damn much, I've updated my signature.

@Urge38, please see link #8 in my sig.

Limits to Oversizing a PV array

How to determine by how much you can oversize a PV array? This can be done with help from the spreadsheet tool. Here though is the manual explanation of how it is done.

There are two limits, when determining the maximum array size that can be connected to an MPPT:

1. The Maximum PV open circuit voltage (Voc at STC)
2. The Maximum PV short circuit current (Isc at STC)

Both values are specified in the datasheets of all our MPPT Solar Charge Controllers. Those two ratings of the PV array must not exceed these MPPT limits.

 

[sunshine_eggo]

It doesnt show up on VRM. If you connect to your SCC via bluetooth you will see it. Every 10 minutes or so it goes to 0 output for 2 seconds.

You can also connect to the MPPT via VRM with VC:







You CAN'T access the device logged TRENDS tab data. This is stored in the BT module, and you must connect via BT to see it. HOWEVER, you can open the TRENDS tab and start capturing live data.

Set your VRM interval to 1m, and you'll often pick up the MPPT sweeps.

 

[ScrotusGobbleBottom]

You can also connect to the MPPT via VRM with VC:

View attachment 190169

View attachment 190171

View attachment 190172

You CAN'T access the device logged TRENDS tab data. This is stored in the BT module, and you must connect via BT to see it.

The Trends TAB is where you will see the gaps im output.

 

[sunshine_eggo]

The Trends TAB is where you will see the gaps im output.

and VRM with 1m log intervals.

 

[AmpD]

Good thread!

I had thought it was like sunshine eggo stated. Glad to see confirmation on it.

So for example I could run 2200w of panels on my 150/45 in 24v mode and only capture 1300w as long as I didn’t exceed the max voltage and current limits.

 

[timselectric]

You can over panel Victron solar charge controllers, it will limit the charging current to the max designed amps or you can lower the charging amps in the settings. My two 100/30 connected to 1200W solar panels each, the 100/50 connected to 1620W solar panels. No problem at all. Running like that nearly 3 years.

That has not been my experience. Serious over paneling (300%) doesn’t seem to bother the ones I’ve used.

I'm not an expert on Victron equipment, or anything even close. My information on Victron is strictly from this forum.

HUH? You know I hate to argue with you, but I think we disagree here...

You know that I am at your mercy when it comes to Victron knowledge.

Array short circuit current, Isc, should not exceed PV input current limit.

But, isn't this what I said?
Maybe I was misunderstood?

 

[740GLE]

I'm not an expert on Victron equipment, or anything even close. My information on Victron is strictly from this forum.


You know that I am at your mercy when it comes to Victron knowledge.

But, isn't this what I said?
Maybe I was misunderstood?

Your first comment of very “limited with over paneling” would imply max PV is determined by the charge current limit. IE don’t exceed 720w 30a at 24v, where that isn’t the case.

Where it might make more sense stick to victrons published limits and you can over panel pretty substantially.

 

[timselectric]

Your first comment of very “limited with over paneling” would imply max PV is determined by the charge current limit. IE don’t exceed 720w 30a at 24v, where that isn’t the case.

Where it might make more sense stick to victrons published limits and you can over panel pretty substantially.

I guess that I was misunderstood.
Overpaneling (to most) means exceeding amperage limits.
But, I suppose the word could also be used for exceeding wattage rating. While remaining below VOC and ISC of controller.
I would not consider that Overpaneling. Because you are within the two limits.

 

[Kiwi2000]

Victron are fine with overpanelling relative to the output of the SCC. In fact they even recommend it.

Have a play with their MPPT calculator and be sure to click on the 'Allow oversizing above 130%' tab.

MPPT Calculator - Victron Energy

MPPT Calculator - Victron Energy

www.victronenergy.com

This is what they have to say about oversizing...

Matching solar modules to MPPT charge controllers - Victron Energy

Life used to be so simple; in a 12V battery system you took a ‘12V’ solar module, watched carefully that the maximum PV current would not exceed the charge controller maximum current and the system would work. Unfortunately due to the fact, that with PWM controllers the PV module is not feeding...

www.victronenergy.com

"You can now for example add the same type of modules in parallel later without the need to change the MPPT charge controller. This reduces costs to a minimum, whilst still increasing the yield!"...

..."The big advantage in doing this is that you will now produce the maximum controller output at a lower irradiation. As module prices decrease, this is an effective option"

I have a couple of strings overpanelled by 200% to Victron SCCs and it works well. Much more consistent yield from day to day under varied weather conditions.

 

[Kiwi2000]

I guess that I was misunderstood.
Overpaneling (to most) means exceeding amperage limits.
But, I suppose the word could also be used for exceeding wattage rating. While remaining below VOC and ISC of controller.
I would not consider that Overpaneling. Because you are within the two limits.

Here's an example I'm running on a 12v system. 1200 watts of PV going to a Victron 100/50. 6 200 watt panels in a 3S2P configuration.

The 100/50 has a max output of 700 watts to a 12v system. But by giving it 1200 watts of panels to draw from, it can reach that 700 watts output for longer through the day and also on those less than ideal days. More consistent output throughout the day and also from day to day.

 

[timselectric]

Here's an example I'm running on a 12v system. 1200 watts of PV going to a Victron 100/50. 6 200 watt panels in a 3S2P configuration.

The 100/50 has a max output of 700 watts to a 12v system. But by giving it 1200 watts of panels to draw from, it can reach that 700 watts output for longer through the day and also on those less than ideal days. More consistent output throughout the day and also from day to day.

I completely understand the reason for overpaneling.
I have done it in extreme fashion.
What amperage were your panels?
What amperage limit for the SCC?

 

[Kiwi2000]

I completely understand the reason for overpaneling.
I have done it in extreme fashion.
What amperage were your panels?
What amperage limit for the SCC?

The panel's Isc is 11.89, so 23.78 amps short circuit for the string.

The 100/50 has a max PV short circuit current of 60A.