Please check my 48V build

[gbrunke]

Hi All,​

Hoping to get some feedback/input on my preliminary design so far. This is my first build so I'm open to hearing anything I might be missing - or not thinking about.

This is for a 2017 Jayco X213. Planning to do full-time travel and want to be able to dry camp/boondock regularly. Typical usage is a pair of laptops, typical 12 RV Loads, microwave, toaster, blender. I am planning on bringing a gaming desktop for a couple hours of occasional use every week or two but it will be powered down except when used. I've started a power usage estimate for what I hope is a heavy use day.

Here is a power usage estimate I started: (link)

Right now the plan is:

• AIO Growatt SPF 3000TL LVM-48P 3000kW/48V
• AOLITHIUM 48V 100Ah (Much less expensive than SOK or EG4 in Canada)
• 1000W+ of PV (Not sure which modules yet until I check the roof space available but the plan is to maximize PV)
• Leave existing 12V house battery (Or buy small LFP) and add a Victron Energy Orion-Tr 48/12-30A

Questions/Concerns:

• Should I add a second 100Ah battery?
• How much solar is realistic for a 24' travel trailer (24'x8')
• Do I need to keep the existing 12V house battery can I just use the Victron DC/DC converter? (Concerned about slide motors burning it up)
• Is the AIO a mistake? (AIO comes across as very cost efficient)
  • does Idle consumption blow my power budget.... can I get away by turning it off?
  • Will the fan noise be unbearable? ( Open to replacing them)
  • Single point of failure (Could add bypass for shore power and I'll have the 12v house battery)

Thanks for your input and help.

 

[rodrick]

I would run 2 batteries running Lifpo4 batteries you don’t worry about charging to 100% every day like fla batteries so with your smaller pv array if you have low pv days you have some extra wiggle room and redundancy

depending on roof congestion like ac units, vents ect probably 750 to 1250 range

i would keep the house battery it will help with surges from the slide motors or other heavy draws

make sure your aio inverter will still work on the scc side even with the inverter off then you only need it on when using ac voltage

aio‘s have good points and bad my mpp units to me are not that bad on noise, idle power more than my victron multiplus but being able to turn off and still charge from pv helps not a deal breaker by any means if your pv is decent size

you might even consider a separate scc that could run a portable ground array you could set up when needed

 

[SamDeleted]

Keep the 12v battery and get the Orion 48/12 , that is a good choice

48v / 100ah battery holds 4.8kwh total . Might be enough, you have to do the maths and figure out your daily usage.


I would bank on needed 2x 100ah 48v battery, 9.6kwh , to help see you through cloudy , low solar production days

 

[gbrunke]

Thanks for the feedback - I ended up ordering two 48V 100AH for the extra margin on days with low PV production.

Looking for some guidance on PV modules for the roof now. I've been trying to fit up all kinds of modules and I think this is the best setup I can get. Limits the number of holes I need to put in the roof and gives me the best coverage.

The modules are Trina Vertex S 390W

https://static.trinasolar.com/sites/default/files/EU_Datasheet_VertexS_DE09.08_2021_A.pdf

Pretty confident I'm going with the Growatt SPF 3000TL LVM-48P.
Maximum PV Array Power: 4000W
MPPT Range @ Operating Voltage: 30VDC ~115VDC
Maximum PV Array Open Circuit Voltage: 145VDC
Maximum Solar Charge Current: 80A

Would 3 modules in a 3S configuration be compatible without any issues?
122.4Voc (STC)
101.4V Mpp (STC)
12.14A ISC (STC)

Thanks

 

[rhino]

Verify noise levels of that Growatt if it is going to be mounted somewhere where noise would be an issue.

Would verify how sturdy those Trina solar panels and/or others using large panels like that on an RV. Larger panels like that are inherently less robust for a mobile application and all warranties I've seen for larger panels immediately void any warranty if put on a mobile structure.

 

[SamDeleted]

Maximum PV Array Open Circuit Voltage: 145VDC

122.4Voc (STC)

It might be too close to your max solar input voltage. Solar panels voltage goes up the colder they get , here is a calculator:

Solar Panel Maximum Voltage Calculator - Footprint Hero

Calculate the maximum open circuit voltage of your solar array. Find your max solar panel voltage to correctly size your solar charge controller.

footprinthero.com

You should be able to get all the specs required from Trina

 

[SamDeleted]

122.4Voc (STC)

So that's 40.8voc per panel ? That's relatively high


If it does turn out to be too many volts with all 3 of those series, you could find lower volt panels that might suit better , eg 36voc~

 

[gbrunke]

So that's 40.8voc per panel ? That's relatively high


If it does turn out to be too many volts with all 3 of those series, you could find lower volt panels that might suit better , eg 36voc~

Using the calculator you linked, I should be good all the way down to -40 degC.

 

[gbrunke]

Verify noise levels of that Growatt if it is going to be mounted somewhere where noise would be an issue.

Would verify how sturdy those Trina solar panels and/or others using large panels like that on an RV. Larger panels like that are inherently less robust for a mobile application and all warranties I've seen for larger panels immediately void any warranty if put on a mobile structure.

Yeah, the Growatt fan noise is a big concern - I'm hoping I can replace the fans with high end PC Cooling fans to knock down the noise level. Any thoughts on mounting the inverter outside in an enclosure on the back of the trailer?

As for the wind load. I'm not really sure how you would check that. The modules are rated for 4000pa of wind load. Using this calculator online
gives me about 290kph/180mph rating which I'm assuming is good but making a pretty big assumption there.

 

[SamDeleted]

Using the calculator you linked, I should be good all the way down to -40 degC.

Fantastic