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12v? 24v? 36...48v????

TurnThePage
Explorer
Explorer
I'm very near to picking up a new travel trailer that I intend to pack with solar and LiFePO4 batteries. It's a 30A 120VAC RV. I understand the electrical wiring advantages of the higher DC voltage configuration, but what does everybody do with their 12v appliances?

I'm hoping for around 1500 watts of solar and no less than 1000Ah of 12v batteries. Is there a good reason not to stick to a 12v configuration?
2015 Ram 1500
2022 Grand Design Imagine XLS 22RBE
71 REPLIES 71

Cptnvideo
Nomad
Nomad
To add to 3ton's comment. On my Victron app which shows max daily outputs of power and voltage, I have noticed I get a higher max daily power output on partly cloudy days.
Bill & Linda, 2019 Ram Laramie 3500 dually 4x4 diesel, Hensley BD5 hitch, 2022 Grand Design Solitude 378MBS, 1600 watts solar, Victron 150/100 MPPT controller, GoPower 3kw inverter/charger, 5 SOK 206AH LFP batteries for 1030 ah

3_tons
Explorer
Explorer
…”although there is no advantage to me doing series on a MPPT, aside from keeping my wire size as small as I can.”

Aside from wire gauge, at higher rooftop temps where efficiencies drop off dramatically (particularly disadvantaging a parallel MPPT config…), a series config can help overcome these afternoon temp related losses, thanks to the higher voltage in reserve…

3 tons

2oldman
Explorer
Explorer
StirCrazy wrote:
but isn't the 150Vdc based on the open circuit voltage not the operating voltage to insure it won't damage the controller if there is an issue?
Yes, I believe that's correct.. which I've never understood. If panels are connected and operating they are not in an open circuit situation. My 6 panels vary between 80v and around 110 in operation, depending on sunlight conditions.
"If I'm wearing long pants, I'm too far north" - 2oldman

StirCrazy
Navigator
Navigator
2oldman wrote:
StirCrazy wrote:
I haven't seen a 30amp mppt that will take a 48v input,
That would be unusual. Many controllers will take up to 150vdc input. It's the output at 48v that might be a little more difficult to find.


I know residential type ones have large inputs and outputs, but isn't the 150Vdc based on the open circut voltage not the operating voltage to insure it won't damage the controler if there is an issue? at least thats how it was expalained to me so if that is wrong please let me know.

my controler for example has a 100V input but it is rated as a 24V in working voltage, but we all know a 24V panel doesnt put out 24V, for example my 325watt split cell panel has a operating voltage of 33.5 and a open circut voltage of 40.3V. so with my controler which can handle upto 100V input that means I could do two 24V panels in series but not three. although there is no advantage to me doing series on a MPPT, aside from keeping my wire size as small as I can.

that wouldn't be a big deal for me to setup as it is only a 8 foot run, and I believe I oversized it to start with incase I did add a second panel.
2014 F350 6.7 Platinum
2016 Cougar 330RBK
1991 Slumberqueen WS100

Boon_Docker
Explorer II
Explorer II
Grit dog wrote:
Boon Docker wrote:
2oldman wrote:
Grit dog wrote:
Hope this helps! Cheers!
Nothing you say helps, but you are quite the comedian.


Yep, pretty laughable.


Meh, at least I contribute…(and am not off base).
Your contribution in 4 days and 7 pages has been 2 ea 1 liner insults?
Yoo can dooo better than that…cmon bud.


I'm just acknowledging what other members have said..
Maybe those comments made by other members would cease if you dialed back your own insults and arrogance.
Give it a try buddy, it might work to your advantage.
.............................................
Quotes from some of your replys to other members in this thread.

Another Derp comment….

Derp….again!
How do you spend so much time geeking out over this stuff and make a comment like that?


Since you can’t seem to take no for an answer.....

^ This post for tuna is gonna be like winding up a toy and turning it loose on the floor!
.....................................................

2oldman
Explorer
Explorer
Grit dog wrote:
You’re running a 48V system in your camper?
Yes.
"If I'm wearing long pants, I'm too far north" - 2oldman

3_tons
Explorer
Explorer
Just More Crickets??

3 tons wrote:
Per StirCrazy : “also at 0 degrees F SiO2 only have 60% of there rated capacity, where LFP has 80% so even in cold situations you have more power available, just have to warm them up to charge, oh wait they have built in heaters also.... “

Sage points spoken…..WHAT SAY PIANOTUNA??

(Note that StirCrazy owns both SiO2 and LiFePO4…).

3 tons


Where’s SiO2 Waldo??

3 tons

Grit_dog
Nomad III
Nomad III
And for all the butt hurt, remember I did not ever say there was anything fundamentally wrong with a higher voltage system. In fact it is more efficient in some ways.
I sometimes make the mistake that I presume that people are after the best balance between cost, performance, durability and value. Served with 2 large sides of practicality.
And I also generally presume that the most apparent cost effective way to competently achieve a particular goal or outcome is desired.

What also I fail to sometimes recognize is there are folks who are just particular about something and prefer it a certain way or “their” way for no obviously advantageous reasons. Heck, I do as well with things. Some things. We all do to some extent.

However, none of this above is “wrong”. Nor would I ever criticize anyone for their preferences generally speaking.

Just state that it’s your preference or you think it’s cool or you recognize that it may not be or isn’t the most cost effective, or something. Because if you don’t, you go from presenting an option to presenting bad information within the context of the question.

Cheers all!
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

Grit_dog
Nomad III
Nomad III
Boon Docker wrote:
2oldman wrote:
Grit dog wrote:
Hope this helps! Cheers!
Nothing you say helps, but you are quite the comedian.


Yep, pretty laughable.


Meh, at least I contribute…(and am not off base).
Your contribution in 4 days and 7 pages has been 2 ea 1 liner insults?
Yoo can dooo better than that…cmon bud.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

Boon_Docker
Explorer II
Explorer II
2oldman wrote:
Grit dog wrote:
Hope this helps! Cheers!
Nothing you say helps, but you are quite the comedian.


Yep, pretty laughable.

Grit_dog
Nomad III
Nomad III
2oldman wrote:
Veebyes wrote:
Sooner or later you will want to sell that RV. Who is going to want what you have done to it by changing the basic DC voltage system?
It's not difficult to revert back to 12v. I'm not giving away all those expensive upgrades to the next guy.


You’re running a 48V system in your camper?
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

Grit_dog
Nomad III
Nomad III
2oldman wrote:
Grit dog wrote:
Hope this helps! Cheers!
Nothing you say helps, but you are quite the comedian.


That’s too bad, apologies.
(You did forget to say that I was also right, though…. I can overlook it. Lol)
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

2oldman
Explorer
Explorer
Veebyes wrote:
Sooner or later you will want to sell that RV. Who is going to want what you have done to it by changing the basic DC voltage system?
It's not difficult to revert back to 12v. I'm not giving away all those expensive upgrades to the next guy.
"If I'm wearing long pants, I'm too far north" - 2oldman

Grit_dog
Nomad III
Nomad III
StirCrazy wrote:
pianotuna wrote:
StirCrazy SiO2 make lifepo4 look bad when truly large draws are needed. So why would I get a battery that has essentially a "limiter" (otherwise known as a BMS) on it at 1 C????


that all depends on the size of the battery and the brand, the dragonfly 270AH LFP have a 300A continuious discharge and peak up to 500A, and thats just having one. if you have 4 of them that gives you 1080AH available and a continuious discharge of aproximatly 1200A if you need it. how many people draw that much?

also at 0degrees F sio2 only have 60% of there raited capacity where LFP has 80% so even in cold situations you have more power available, just have to warm them up to charge, oh wait they have built in heaters also....


^ This post for tuna is gonna be like winding up a toy and turning it loose on the floor!
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold