Victron MPPT over panelling

timselectric · Jan 20, 2024

Kiwi2000 said:
The 100/50 has a max PV short circuit current of 60A.

Really?
That's awful high.
There shouldn't be any issues with that, at all.

Kiwi2000 said:
The panel's Isc is 11.89, so 23.78 amps short circuit for the string.

How would this be considered overpaneling?

Wait, it's a 12v system using a SCC capable of 48v.
So, it would be very hard to overpanel on a 12v system.
Because it's not capable of even using, up to the limited amperage.

Kiwi2000 · Jan 20, 2024

timselectric said:
Really?
That's awful high.
There shouldn't be any issues with that, at all.

How would this be considered overpaneling?

Wait, it's a 12v system using a SCC capable of 48v.
So, it would be very hard to overpanel on a 12v system.
Because it's not capable of even using, up to the limited amperage.

Here's the specifications for the 100/50...

https://www.aeppacific.co.nz/wp-content/uploads/2018/10/Victron-SmartSolar-charge-controller-MPPT-100-30-100-50.pdf

It can only do 12 or 24 volt systems.

Overpanelling is when there is more watts of PV than what the maximum output of the SCC is capable of outputting to its particular system. It means there will be clipping as the SCC becomes maxed out rather than having a SCC that can output as much PV wattage that is attached to it.

timselectric · Jan 20, 2024

Kiwi2000 said:
Here's the specifications for the 100/50...

https://www.aeppacific.co.nz/wp-content/uploads/2018/10/Victron-SmartSolar-charge-controller-MPPT-100-30-100-50.pdf

It can only do 12 or 24 volt systems.

Overpanelling is when there is more watts of PV than what the maximum output of the SCC is capable of outputting to its particular system. It means there will be clipping as the SCC becomes maxed out rather than having a SCC that can output as much PV wattage that is attached to it.

Victron is a different animal.
With other equipment, the wattage output closely matches the voltage and amperage limits.
Overpaneling usually requires exceeding the input amperage limit.
I suppose it is different because of the multiple battery voltage capabilities.
This is usually why I defer the Victron questions to @sunshine_eggo lol

Kiwi2000 · Jan 20, 2024

timselectric said:
Victron is a different animal.
With other equipment, the wattage output closely matches the voltage and amperage limits.
Overpaneling usually requires exceeding the input amperage limit.
I suppose it is different because of the multiple battery voltage capabilities.
This is usually why I defer the Victron questions to @sunshine_eggo lol

Epever has a 1.5 times maximum PV input wattage relative to the SCC's output wattage.

Overpanelling is commonly thought of as having more PV wattage than the charge controller can output.

ie...

Anyone over-paneling an EPEVER MPPT?

I’m interested in anyone overpowering an Epever MPPT charge controller. Are there any issues? Is there any upper-limit (assuming you don’t care about wasted potential power generation if you max out)? I’m thinking of powering a 40A / 1000W Epever MPPT with 3x450W panels (35% overpanelling)...

diysolarforum.com

"1800W of panels feeding a 1200W SCC is 50% over paneling, about the maximum that makes sense (unless you have a very particular situation) and close to the maximum that Epever specifies.

I have the 200V model of their SCC but the manual specifies a maximum of 1875W PV power for the 1250W-rated 5420AN (as well as the 150V 5415AN).

1875 / 1250 = 150% (exactly)."

timselectric · Jan 20, 2024

Again, multiple battery voltages.

I still think that my original statement stands true.
You have to be careful with overpaneling Victron SCC's. Too many amps will damage them.
Unless I misunderstood previous conversations on how they operate.

Kiwi2000 · Jan 20, 2024

timselectric said:
Again, multiple battery voltages.

I still think that my original statement stands true.
You have to be careful with overpaneling Victron SCC's. Too many amps will damage them.
Unless I misunderstood previous conversations on how they operate.

Then why do Victron even have an option for "Allow oversizing above 130%" on their MPPT calculator...

MPPT Calculator - Victron Energy

www.victronenergy.com

If it were simply do not exceed max voltage and input amps then they wouldn't even talk about oversizing. (the SCC would simply go up in a puff of smoke the moment maximum inputs were exceeded)

No, oversizing is in relation to the watts of PV relative to the max wattage output of the unit.

timselectric · Jan 20, 2024

Kiwi2000 said:
the SCC would simply go up in a puff of smoke the moment maximum inputs were exceeded

It was my understanding that they very well could.
If input amperage was exceeded.
@sunshine_eggo please correct me if I'm wrong.

Kiwi2000 · Jan 20, 2024

timselectric said:
It was my understanding that they very well could.
If input amperage was exceeded.
@sunshine_eggo please correct me if I'm wrong.

Of course they would. That's why they state not to go over the maximum voltage rating and amperage input rating.

But that's not what they're talking about when they talk about oversizing PV relative to the SCC output.

AntronX · Jan 20, 2024

I run my 75/15 with PV input connected to 630Ah battery, so it's effectively as overpaneled as wire resistance will allow. I have 5A fuse in line. It never blew yet. So I kinda doubt Victron shorts PV input as part of MPPT routine. Or maybe MPPT never runs when it detects "infinite" power source. Makes this thing into neat little 48V > 12V dc converter with bluetooth!

sunshine_eggo · Jan 20, 2024

timselectric said:
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.

It was these parts. Victron provides very clear guidance on over-paneling their MPPT. Their MPPT calculator regularly recommends up to 30% over-paneling just because you're not missing much in most cases.

While a 250/100 (what I have) could only put out 1450W to a 12V battery, one could safely hang about about 11,000W@ 170Vmp and 65A Imp. That's over 700%.

It gets even more absurd with the 450/200. EACH tracker (4) can safely be over-paneled to about 8,300W... there's 4 trackers, so about 33kW even though it can only output about 11kW.

timselectric said:
It was my understanding that they very well could.
If input amperage was exceeded.
@sunshine_eggo please correct me if I'm wrong.

Kiwi2000 said:
Of course they would. That's why they state not to go over the maximum voltage rating and amperage input rating.

But that's not what they're talking about when they talk about oversizing PV relative to the SCC output.

Nope. The PV input current limit is the maximum Isc the array can have and still retain reverse polarity protection. If you don't hook your array up backwards, then there's no hard limit - except on the aforementioned RS 450/200 (they explicitly state it's a hard limit).

It probably runs up against a sanity limit. It would be insane to put 30kW on a controller only capable of outputting 5800W

Checkthisout · Jan 20, 2024

I overpanelled a cheap renogy 40 amp to probably 5x its limit. I had 10 panels on it and disconnected them 1 by 1 until it was just two panels pushing it to 42 amps. So it had handled the extra 8 just fine.?

It output 42 amps and just got warm/hot and kept on ticking. I would guess it's heat rejection was in the order of 50-70 watts.

My current Epever was at 12 volts 100 amp is sitting on 2470 of panels.

Same deal 1 sunny day in July. It just kept it to like 98 amps while the panels went to full open circuit voltage. Controller gets warm but nothing to write home about.

740GLE · Jan 20, 2024

timselectric said:
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.

So in your world over paneling is a 30A SCC outputting more than 30a?!? Or just an SCC allowing higher VOC than published specs, like midnites?

I always thought over paneling was just having more name plate PV connected to the SCC than it could output.

Do all SCC post ISC limits?

timselectric · Jan 20, 2024

740GLE said:
So in your world over paneling is a 30A SCC outputting more than 30a?

No
I would assume that is impossible.

740GLE said:
Or just an SCC allowing higher VOC than published specs,

Never

740GLE said:
I always thought over paneling was just having more name plate PV connected to the SCC than it could output.

This basically.
But since Victron has multiple voltage output options. It appears that it has multiple options for overpaneling. As long as you never exceed the ISC hard limit.

740GLE said:
Do all SCC post ISC limits?

Nope, only a few post hard limits.

timselectric · Jan 20, 2024

Checkthisout said:
I overpanelled a cheap renogy 40 amp to probably 5x its limit. I had 10 panels on it and disconnected them 1 by 1 until it was just two panels pushing it to 42 amps. So it had handled the extra 8 just fine.?

It output 42 amps and just got warm/hot and kept on ticking. I would guess it's heat rejection was in the order of 50-70 watts.

My current Epever was at 12 volts 100 amp is sitting on 2470 of panels.

Same deal 1 sunny day in July. It just kept it to like 98 amps while the panels went to full open circuit voltage. Controller gets warm but nothing to write home about.

Last winter I had 90a worth a panels connected to an 18a SCC. I had full output from sunrise to sunset. lol

740GLE · Jan 20, 2024

timselectric said:
No
I would assume that is impossible.

Never

This basically.
But since Victron has multiple voltage output options. It appears that it has multiple options for overpaneling. As long as you never exceed the ISC hard limit.

Nope, only a few post hard limits.

So what’s your definition of over paneling?

Do you have your favorite SCC that you consider over paneling friendly?

timselectric · Jan 20, 2024

740GLE said:
So what's your definition of over paneling?

Connecting more PV than a SCC can use.
Since most MPPT's have voltage and amperage limits that closely add up to the wattage. It usually means over amperage. (Since overvoltage is damaging)

740GLE said:
Do you have your favorite SCC that you consider over paneling friendly?

Most are, if they don't post hard ISC limits.
I know that my Growatt's have no problem with it.
And members have reported several others. I don't remember exactly which ones they were. But I'm sure that all of the Voltronics based ones are fine with it.

AntronX · Jan 20, 2024

Any well designed MPPT controller should have output overcurrent protection or any software glitch will let the smoke out. It should only drink what it needs from the firehose.

Checkthisout · Jan 20, 2024

Exceeding the PV VOLTAGE limit is akin to plugging a 120V appliance into 240 Volt.

Urge38 · Jan 21, 2024

Wow

My most replied to thread too date !!!!

I started this topic, simply on the assumption that I trusted my TriStar mppt over the possible new addition of a victron.

(I have a TriStar 45a mppt and wanted to add a 20a mppt and found a good deal on the Victron)

This is all a assumption mind
But TriStar controller are a lot more money than vicron

If TriStar gives a limit of 130% too over panelling (ie wattage not voltage) then why does the cheaper victron not mention it other then so say the mppt will deal with it

That was my logic that prompted my question

Pi Curio · Jan 21, 2024

You can over-panel Victron SCC as much as technically possible, that is, within its Voc and Isc limits.

I have Victron 100/20@12V(290W max) currently, and with enough panels, I could go and over-panel it by 500% or 1600W of solar in summer or 400% in winter.

Obviously, I'd never go with 500% as it matches the SCC Voc, but even 400% over paneling is a lot on this small 100/20 beast.

As Sunshine mentioned, you could even over-panel a bit more over the Isc limit, but in case of reverse polarity or short-circuiting of the PV input, the SCC can no longer protect itself.

So, staying within Voc and Isc limits with a bit of headroom is the best practice.

Victron MPPT over panelling

If I can do it, you can do it.

Solar Enthusiast

If I can do it, you can do it.

Solar Enthusiast

If I can do it, you can do it.

Solar Enthusiast

If I can do it, you can do it.

Solar Enthusiast

DC Powered

Happy Breffast!

Solar Wizard

Solar Wizard

If I can do it, you can do it.

If I can do it, you can do it.

Solar Wizard

If I can do it, you can do it.

DC Powered

Solar Wizard

New Member

Sunlicious

Similar threads