Sanity check needed - adding additional soalr capability to an XV-JP

[Pgopinath]

Hello:

I have an Earthroamer XV-JP (Jeep Rubicon based RV) which has an 80W Sharp panel installed on the roof. It uses a Blue Sky 2000E 2A/12VDC MPPT as the charge controller. This has a Max PV Power of 340W at STC and a Max PV current of 20A

My battery bank consists of two Lifeline 110AH AGM batteries. I am considering replacing this with qty 3 X 120AH LiFePO4 = 360AH of LiFePO4.

I would like to get to an end state config consisting of the current Sharp 80W, qty 2 of Kingsolar flexible solar panels each at 120W, and a Goal zero 100W suitcase to be used when parked in the shade. The two flex panels are the max i can fit on the remaing roof real estate. https://smile.amazon.com/dp/B017QYS...olid=1Y3XQXW3M5EY1&psc=0&ref_=lv_ov_lig_dp_it

Why:

1. The current solar panel is mounted above the cab. I usually park the vehicle to shade the cab so the Sharp panel doesn’t get any sun when I am camped.
2. The sleeping area of the vehicle is a flip over roof. I want to add additional panels on this. When the flip roof tent is not deployed this area is exposed and can catch sunlight.
3. When the sleeping area is deployed and the cab is in the shade as is typical for campsites I need to be able to place an aux panel away from the vehicle but plugged in. This is the motivation for the suitcase panel noted.

With the above complement of solar panels the maximum that would connected to the charge controller at any one time would be 320W (80W + 240W) which would be when I am driving or parked in the sun.

Questions:

1. The current Sharp 80W panel is not easily removable and appears to be out of production. So i have to go with dissimilar panels to squeeze the maximum power out of my available real estate. Is this okay or should i get a separate CC for the add-on solar panels?
2. What is the most effective way to connect these panels to the charge controller. Should I just parallel them all so the charge controller is presented with 320W total at 12V?
3. Can I similarly run the inputs for the suitcase panel so that when it is hooked up it is paralleled to the fixed roof mounted panels (which will obviously not be generating any PV power since they will not be exposed to sunlight)?

Is there any additional advise you have for me? I will be grateful for any direction that will help me implement this correctly.

Thanks
Prabha

 

[dwh]

Those flexi panels have a Vmp of 21v. What is the Vmp of the Sharp? They have to be reasonably close - within a couple volts of each other.

If they are close enough, you should be fine with the controller you have.

Again, if the Vmp is close enough parallel would be fine.

 

[krick3tt]

My panel is not fixed as yours is. When I require an additional panel I do connect it in parallel. My requirements for additional panels does not arise often as my travels seem to allow the aux battery to maintain a proper voltage from the vehicle charging system. Staying parked for more than two days is troublesome. Most of the folks I travel with have movable panels.
I have not been able to park in the shade often but when I do my panel, being a fold up panel, is able to be located and properly orientated in a sunny location.
I opted for a fixed panel once but found it to be limiting. Also took up needed room on the roof rack. Having this new 100W panel is better and seems to be adequate for my simple needs. I believe the new panel is 18V and routed through charge controller that is only used while parked.

 

[Pgopinath]

Because more than 2/3 of the roof flips over to become the sleeping area I can put a roof rack on the vehicle anyway. So a couple of flexible solar panels are the best thing i can throw up there.

The current solar panel has a Vpm of 17.3V

According to Amazon the Kingsolar panels I am considering are speced as follows:
Specifications:
*Peak-power: 120W
*VPM(V):18V
*Maximum current(A) :6.67A

I think they are close enough that i can parallel the three panels.

Looking forward to getting this done.

Thanks everyone
Prabha

 

[dwh]

That's from the link you posted. It says 21.3v.

Either way it'll work, with a slight loss of efficiency as the MPPT splits the difference. Make sure the portable panel is in the same ballpark.

 

[rayra]

I found it relatively easy to make a rooftop panel mounting frame that could be unlocked to release the panel so it could be positioned on the ground in the sun with the vehicle left in the shade. It would be fairly easy / straightforward to make a similar frame for just about any panel or mounting location. With a wide variety of latches or locks. All you need is some channel / extrusion to craft the frame such that the panel slides into it and one end or side of the frame hinged or attached in a way that it's easy to release the panel. Details are on page 9 of my build topic.
All you have to do is build a picture frame sort of arrangement, using c-channel, making sure not to obscure the cells.

 

[IdaSHO]

I use a combination of roof panels and ground deployed panels.

All rigid panels, ground deployed are custom DIY briefcase types, wiring to produce a 24V ground array to match out roof panels.

Roof panels were installed with a bit of aluminum angle and bolts/pins that can be removed and legs inserted, to allow for tipping in 4 directions.
Although I never did get the front and back pivot brackets, as I decided left and right was enough,
as we tend to park N-S anyhows, to catch a sunset/sunrise through the entry door (side entry)

But the simple brackets, with just 4 wing-bolts, wing nuts, and safety pins are all that keep the panels on, and could be an easy solution for
roof panels that could be removed and deployed on the ground.

 

[rayra]

Are you also able to release the bolts on one side and tip the panels up at an appropriate angle?

 

[IdaSHO]

Yes, they can be tipped/angled.

I carry 3 sets of aluminum legs (nothing more than 3/16" aluminum flat bar) in 3 different lengths for 3 different angles, for both panels. We have two on the roof.

 

[Pgopinath]

Following up on my original post. I connected with the technical support at Blue Sky and got some useful information back. Copied below :
>>>>>
Sorry about the delay in responding. The SB2000E is rated to 340W of input, max recommended Voc 24V, so yes technically you could use all your panels. I would connect them all (including the optional folding panel, when desired) to the SB2000E (wired in parallel), with the exception of having your rooftop array's combined positive output run through a blocking/ anti-reverse diode so that if the roof panels are obscured (shaded), they will not drag down the energy production of your folding panel.
https://www.amazon.com/uxcell-Anti-...&sr=8-2-spons&keywords=anti+reverse+mc4&psc=1

Since most panels only produce ~7-% of their STC rated wattage in "real life", you might be able to use all your panels (Roof & folding) together. As long as the output of the SB2000E does not spike at 25A, you are not stressing out the controller. The controller will limit it's output to it's maximum if excess PV input current/ wattage is available.

Lastly, When we first developed the SB2000E, the industry standard was 2-stage charging. Since then everybody, including ourselves, have transitioned to 3-stage charging.The SB3000i is a 3-stage charger and is a drop in replacement for the 2-stage SB2000E with optional automatic or manual equalization. It boasts digitally programmable charge voltages and has optional 2A auxiliary battery maintainer or 20A Low Voltage Disconnect (LVD) with Dusk to Dawn Lighting capabilities.

http://www.blueskyenergyinc.com/uploads/pdf/SB3000i_Datasheet_(2017)_3.pdf

http://www.blueskyenergyinc.com/faq/

You can program the SB3000i to Lifelines exact charge specifications (14.3V absorption, 13.3V float, 39mV/C/C* temp comp), extending their lifespan. I would also recommend utilizing a temperature sensor. If you would like to upgrade your unit let me know and I'll provide a 20% off MSRP coupon.

http://www.blueskyenergyinc.com/uploads/pdf/BattTempSensor_930-0022-20_Datasheet_(2017).pdf

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[EKBCPA]

Prabha,
What number XV-JP do you have? I have #0000, first one built (prototype).
Eric

 

[Pgopinath]

Eric:

My XV-JP is #11. If it is convenient I would like to see how you interior is laid out. I am trying to modernize the interior with products that are available today and probably weren't available or were too large back in 2008.
Regards
Prabha