Adding a panel to factory panel questions.....

[Puma1973]

I have a 2022 390rk-r with factory installed 300W panel. I would like to add to that. From researching, I believe that the controller will only work well to the lowest panel capacity. With this being said, I assume that means I should install another 300W panel to get some more charging capacity. Is that correct? Going with a 400W panel would be a waste?
Has anyone added to the factory panel? If so, how does one connect the 2 panels? Any links to items required? What panel do you recommend?
Any tips/advice appreciated..

Already installed:
Victron MPPT 100/30 controller
Victron shunt
(3) 100AH lithiums - thinking of adding 1 more

 

[brandtb1919]

I have a 2022 390rk-r with factory installed 300W panel. I would like to add to that. From researching, I believe that the controller will only work well to the lowest panel capacity. With this being said, I assume that means I should install another 300W panel to get some more charging capacity. Is that correct? Going with a 400W panel would be a waste?
Has anyone added to the factory panel? If so, how does one connect the 2 panels? Any links to items required? What panel do you recommend?
Any tips/advice appreciated..

Already installed:
Victron MPPT 100/30 controller
Victron shunt
(3) 100AH lithiums - thinking of adding 1 more

I am assuming that your battery bank is 12V since you have an odd number of batteries. The spec sheet for the 100/30 MPPT says that the max power output for a 12V system is 440W. If you add more than a 100W or so to your array, you are leaving power on the table.

If you were to upgrade to the 100/50 MPPT that has a max output of 700W, so adding a 400W panel would fully utilize the size of the MPPT in theory (It is nearly impossible to get full rated output from a panel).

I would recommend putting the panels in series since the controller is capable of 100V input. Putting them in series also makes it so you don't have to worry about the panels being identical.

Brian

 

[Puma1973]

I am assuming that your battery bank is 12V since you have an odd number of batteries. The spec sheet for the 100/300 MPPT says that the max power output for a 12V system is 440W. If you add more than a 100W or so to your array, you are leaving power on the table.

If you were to upgrade to the 100/50 MPPT that has a max output of 700W, so adding a 400W panel would fully utilize the size of the MPPT in theory (It is nearly impossible to get full rated output from a panel).

I would recommend putting the panels in series since the controller is capable of 100V input. Putting them in series also makes it so you don't have to worry about the panels being identical.

Brian

Of course I installed the wrong controller.. Not knowing enough at the time I purchased it, my fault completely.
Would charging time be reduced enough to warrant going with a 400W panel and changing out the controller. Or would just another 100W panel make more sense in my situation?

I could upgrade to the 50.
Can you shed some light on how to go about panels in series, so I could just add a 400W panel and be good with things? (assuming i swap to the 50 MPPT)
Obviously I am a newbie. Have mechanical skills just need the knowledge to make sure I do things/purchase correctly.

 

[brandtb1919]

Of course I installed the wrong controller.. Not knowing enough at the time I purchased it, my fault completely.
Would charging time be reduced enough to warrant going with a 400W panel and changing out the controller. Or would just another 100W panel make more sense in my situation?

I could upgrade to the 50.
Can you shed some light on how to go about panels in series, so I could just add a 400W panel and be good with things? (assuming i swap to the 50 MPPT)
Obviously I am a newbie. Have mechanical skills just need the knowledge to make sure I do things/purchase correctly.

I'm usually a go big or go home type of guy (when I can afford it!). In my opinion, an extra 100W is not a very big gain. It'll get you about an extra 5-7A into the bank, perhaps charging from depleted a few hours faster.

IMO, if you are even considering more batteries, I would upgrade the controller and at least double the panel wattage (add another 300W). That's just me.

Connecting the panels in series is as easy as it gets. Connect a + and - from each panel to each other, and the free + and - to the controller. Parallel would be + to + and - to - going into the controller.

I should clarify that it is always best practice to have the panels as closely matched as possible if going into the same controller. It is most critical for parallel operation so that the voltages match. There is a lot of debate about series or parallel, or a combination for best operation.

I have some posts on here showing what I did with my rig.

 

[Puma1973]

I'm usually a go big or go home type of guy (when I can afford it!). In my opinion, an extra 100W is not a very big gain. It'll get you about an extra 5-7A into the bank, perhaps charging from depleted a few hours faster.

IMO, if you are even considering more batteries, I would upgrade the controller and at least double the panel wattage (add another 300W). That's just me.

Connecting the panels in series is as easy as it gets. Connect a + and - from each panel to each other, and the free + and - to the controller. Parallel would be + to + and - to - going into the controller.

I should clarify that it is always best practice to have the panels as closely matched as possible if going into the same controller. It is most critical for parallel operation so that the voltages match. There is a lot of debate about series or parallel, or a combination for best operation.

I have some posts on here showing what I did with my rig.

I think that I will take your advice and switch out the controller and go with an additional 300W panel.
One more question for you, connecting the panels, is this just a matter of the correct connectors and making the connection on the roof at panels, or is it more complicated and I need to run wires down thru chase and to near controller and modify connections there? Can you point me towards connectors that would be required to do this?

 

[brandtb1919]

I think that I will take your advice and switch out the controller and go with an additional 300W panel.
One more question for you, connecting the panels, is this just a matter of the correct connectors and making the connection on the roof at panels, or is it more complicated and I need to run wires down thru chase and to near controller and modify connections there? Can you point me towards connectors that would be required to do this?

The connectors that normally come on the panels are called MC4 connectors and are gendered such that one is the negative wire and the other is the positive wire. I am assuming that you are using the factory GD connector box on the roof. If so, the wiring that they ran is good for about a max of 30A. You will be well within this with the panels in series (about 15A).

The MC4 connectors will allow you to connect them in series, as well as connect to the box on the roof (I think, I've never opened mine). If you don't have any fuses in place, I would suggest at the least, an in-line MC4 fuse. I prefer to have a breaker in the compartment with the MPPT controller for servicing. Victron also recommends that the solar panels be connected last and disconnected first. If any new or replacement connectors are needed, they can be bought on amazon along with the crimpers. A diagram of the connection is below:



Brian

 

[huntindog]

I think that I will take your advice and switch out the controller and go with an additional 300W panel.
One more question for you, connecting the panels, is this just a matter of the correct connectors and making the connection on the roof at panels, or is it more complicated and I need to run wires down thru chase and to near controller and modify connections there? Can you point me towards connectors that would be required to do this?

There is more to it than has been discussed so far.
Read this before going any further:https://solarpanelsvenue.com/mixing-solar-panels/

If you are buying another controller. you can get full power from both panels if they are on seperate controllers.

You could add a larger controler for additional panels,thenyou could add more of the same panels at will. The factory 300 watt panel was impossible to match when I was doing mine. One would need to buy another factory panel at a ridiculous price.

 

[brandtb1919]

There is more to it than has been discussed so far.
Read this before going any further:https://solarpanelsvenue.com/mixing-solar-panels/

If you are buying another controller. you can get full power from both panels if they are on seperate controllers.

You could add a larger controler for additional panels,thenyou could add more of the same panels at will. The factory 300 watt panel was impossible to match when I was doing mine. One would need to buy another factory panel at a ridiculous price.

This can be a very deep rabbit hole for sure.

 

[Puma1973]

There is more to it than has been discussed so far.
Read this before going any further:https://solarpanelsvenue.com/mixing-solar-panels/

If you are buying another controller. you can get full power from both panels if they are on seperate controllers.

You could add a larger controller for additional panels,then you could add more of the same panels at will. The factory 300 watt panel was impossible to match when I was doing mine. One would need to buy another factory panel at a ridiculous price.

So let me see if I am understanding you guys correctly:
Instead of replacing my current controller with one that could handle more wattage and selling my current controller. The best practice may be to buy say a 400W panel ($200 +/-) and another controller, say that just handles the 400W panel ($125) and use these in addition to what I already have. This route would just require running new wire from roof to front bay where controllers and batts are. This option would assure I am getting the most from my panels. Am I picking up what you guys are throwing down?

 

[huntindog]

So let me see if I am understanding you guys correctly:
Instead of replacing my current controller with one that could handle more wattage and selling my current controller. The best practice may be to buy say a 400W panel ($200 +/-) and another controller, say that just handles the 400W panel ($125) and use these in addition to what I already have. This route would just require running new wire from roof to front bay where controllers and batts are. This option would assure I am getting the most from my panels. Am I picking up what you guys are throwing down?

Yes. If you get another Victron they will synch up and operate in lockstep.
If you have room on the roof for more panels, you may want to get a controller large enough to handle future expansion. Solar is often addicting.
I run two Victrons myself. I also started out with the Factory 300 watt panel. When I looked into adding another one, it was more than $700.00!!!

 

[Puma1973]

Thanks for the help guys. I think I will stick with the factory panel and add an additional panel and controller.