Charge Controller PV Input Limits

[KnobCountry]

My portable powerpack have a warning on it.
Max solar panel 80watts 24 volt on the mppt .
Strange the same connection is use to set a carlighter plug on it and than i charge with 10amps .
It draw 120watts on that moment.

So one mppt is not the same like a other.

My epever solar charger warning is that max 260watt by a 12 volt battery .
Do not go over it , it can damage the controller.
Its a 20amp model
In the Manuel.

On the victron 75/15 it tell max 220watt solar panel.
If its connect with more it will not use it but no damage.

What model is the epever? Sounds more like a pwm cc.

 

[Suijkerbuijk]

What model is the epever? Sounds more like a pwm cc.

Epever traver serie

 

[timselectric]

I suppose if one over-paneled too much it could cause the controller to be outputting it's max for a longer period of time and thus could shorten it's life. Especially if it's cooling system is not great.

This is a possibility.
I ran 98 panels (23.7 kw , 80a) on a single MPPT (6 kw , 18a max) for several months.
It was running max production from sunrise to sunset.
But my equipment is in a conditioned space, so it stays cool no matter how hard it's working.

 

[ddxv]

The amperage rating is based on the limits of reverse polarity protection.
As long as you don't connect the PV circuit in reverse polarity. You can make as much as you want available.
But if that maximum is exceeded, and connected in reverse polarity, damage can occur.

I've heard this before in other threads. How does reverse polarity happen? Just literally plugging in the negative and to positive?

 

[timselectric]

I've heard this before in other threads. How does reverse polarity happen? Just literally plugging in the negative and to positive?

Yes
Connecting it backwards, by accident.

 

[haycord]

This is a possibility.
I ran 98 panels (23.7 kw , 80a) on a single MPPT (6 kw , 18a max) for several months.
It was running max production from sunrise to sunset.
But my equipment is in a conditioned space, so it stays cool no matter how hard it's working.

I don't understand - when yall are talking about 'max production' isn't that dependent on CC Output Limit and/or the active Load?

 

[timselectric]

I don't understand - when yall are talking about 'max production' isn't that dependent on CC Output Limit and/or the active Load?

Yes
It's dependent on output and input limits.
And the loads connected.
For instance, my SCC can input a maximum of 18a, and output a maximum of 100a @ 48v nominal. Both limits will never be exceeded by the SCC.
When I say maximum production, I'm referring to the 18a limit.
Wattage is dependent on the voltage, when the amperage is at maximum.

 

[haycord]

Yes
It's dependent on output and input limits.
And the loads connected.
For instance, my SCC can input a maximum of 18a, and output a maximum of 100a @ 48v nominal. Both limits will never be exceeded by the SCC.
When I say maximum production, I'm referring to the 18a limit.
Wattage is dependent on the voltage, when the amperage is at maximum.

Very good, thanks.

 

[haycord]

I'm going to take a stab and say this:

Overpaneling (exceeding the CC PV Input Power Limit) will allow the Array to provide more power during low-light conditions. During times of maximum Array output - the CC will limit its output to that specified (ie: 40A) regardless of any excess current available at the Array. Obviously when the CC limits its output it naturally limits its input demand.

FYI Update: I contacted Rich Support about their 40A MPPT and asked if I could exceed the stated 1100W max PV input and connect 1400W. They said no problem - the SCC will not draw more power than is needed to meet the 40A output rating. Exactly as many of you said. Obviously the Voc is a hard limit. Thanks again for everyone's help.

 

[ddxv]

FYI Update: I contacted Rich Support about their 40A MPPT and asked if I could exceed the stated 1100W max PV input and connect 1400W. They said no problem - the SCC will not draw more power than is needed to meet the 40A output rating. Exactly as many of you said. Obviously the Voc is a hard limit. Thanks again for everyone's help.

I've also been asking on Midnite forums about it, and user boB there said something similar for exceeding PV input for the Classics:

If you severely over-panel a Classic, or most MPPT controllers, it will current limit but it does this by raising the PV input voltage.

Running the controller at full output current at higher input voltage makes the controller run hotter is all.

Yes, it might also take a bit longer to current limit. Have to take each situation individually.

boB