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Old 02-13-2019, 09:53 AM   #61
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1985 31' Excella
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Quote:
Originally Posted by Ponobill View Post
I don't intend to be argumentative, it's simply that there's a lot more to consider in sizing batteries, panels, controllers and inverters. Here's an example from an article I wrote in my blog. A typical Coleman Mach8 heat pump draws 16 amps at 115VAC, or 1840 watts. Ignoring small inverter efficiency losses that means 76 amps at 24VDC. Starting current is around 60 amps at 115V, so 6900 watts or 290 amps at 24VDC.



You can encounter similar differences in starting current for any AC reactive load.



Here's a link to the article: https://www.ponostyle.com/solar-power-for-rvs/ There's also an article about wire size there. I haven't gotten around to writing more.

With out assumptions [ and there is the acronym for assume ] it hard to talk about almost any subject .
To help reduce assumptions , converting the most basic info to numbers & the most basic numbers for this subject " can I run everything " is Ohm's Law , the primary rule to gather the numbers required to answer the question .
Then for the general subject of solar , there are so many variables to each individuals wants / needs , that anybody wanting to have solar needs basic measuring to design a specific system to there individual future system .
In any endeavor , you start from standards that expressed in numbers .
So the need for Ohm's Law , simple enough that most anyone can learn to use .
Even if everyone is not going to engineer there own system , the numbers allow for not being sold a bill of goods , and that is a huge issue with shopping for solar .
I see threads here making claims , that I do not even have to getout a paper & pencil , knowing Ohm's Law , I can roughly estimate numbers in a thread / and many times the lack of numbers , and say to myself - that will not work .
Just trying to help get others that ask " can I run everything " on a basic footing to work out some of the issues .
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Old 02-15-2019, 07:36 AM   #62
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Thanks everyone for the continued supply of great info!

Looking at the numbers, with a little discipline I think it is very possible to full-time exclusively off solar (especially in NM) supplemented only by generator power.

Wolfwhistle, I am a good ol boy from Oklahoma... spit-balling is kinda like the country way of saying brainstorming :P . As to the clothes dryer, I have indeed been pondering ways to fit a 120v washer / dryer combo in the rig.
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Old 02-15-2019, 06:42 PM   #63
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Margaritaville , Banana Republic
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My L1 feed from shore power passes through a breaker on my main panel delivering 120v / 50A AC to the inverter, which passes through and then supplies 120v / 50 AC back to the sub panel on which most everything in the trailer is powered (with the exception or rear aircon and electric hot water element)
Thanks W. I read back into the thread and see you have 50 amp load center. And a subpanel.
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Old 02-15-2019, 06:49 PM   #64
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Originally Posted by Lindenwood View Post
Thanks everyone for the continued supply of great info!

Looking at the numbers, with a little discipline I think it is very possible to full-time exclusively off solar (especially in NM) supplemented only by generator power.

Wolfwhistle, I am a good ol boy from Oklahoma... spit-balling is kinda like the country way of saying brainstorming :P . As to the clothes dryer, I have indeed been pondering ways to fit a 120v washer / dryer combo in the rig.
You wrote spit-balling I was thinking split... something. Thanks. When "spit-balling" remember a washer uses quite a bit of water. Only setup I've seen for this would entail full hookups since the washer discharges directly to the dump valve... not into the holding tank, which would quickly fill up anyway.
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Old 02-15-2019, 06:53 PM   #65
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1968 26' Overlander
CORDOVA , TN
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Originally Posted by wulfraat View Post
At 75 or so degrees outside troutboy ran his AC for about 3 hours or so on 400ah of lithium IIRC.

At 90 degrees Iíve run my 15k penguin II pretty much pegged for 2+ hours with no issues with 600ah, and still had capacity to spare.

While running when itís hot out, the AC will ramp up and peg at just about 1,800 watts draw from the inverter. (I have a multiplus 3k rated at 2,400 watts continuous output)

With a few other house loads (likes our ice maker, television, fridge on LP, etc) and inverter losses your drawing about 2,000 - 2,200watts or about 150-165 amps from the batts continuously (the AC compressor does not cycle often when itís really hot out).

As a point of reference 3 hours at this load is 450-500 amp hours or 75%-80% of total capacity for my lithium bank, assuming your starting with 100% in the morning. Then things get dark Ďcause youíve used all your capacity

However! Solar helps big time! When itís nice and sunny out in June my panels will generate peak output of 600 to 800 watts (42-55 amps @14.2v to the batteries!) between 10.30a and 1.30p to help offset the power draw from the batts... extending timeframes / leaving some power for overnight.

We regularly run our AC for 1 hour + when stopped for lunch on the road, etc. itís super convenient.

If itís gonna be a really hot and long day, and we are at camp, and itís not an annoyance to others, Iíll run my little honda 2000 on propane and pull 10-12amps from it as shore power, and use the hybrid function of the multiplus to supplement that with battery and / or solar energy to supply the AC. I can pretty much run all day in hybrid mode. I rarely get 15 amps @120v from my honda because we tend to camp above 8,000 feet so output is reduced on the genset.

Lithium rocks. And we like our little mini sonic ice maker which requires ďalways onĒ 120v house power who doesnít like a nice cold cocktail after a long day of hiking or cycling
Dude the ice maker is wicked !
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Old 02-16-2019, 09:09 AM   #66
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1985 34' Excella
Hood River , Oregon
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I Mis-spoke, my inverter is a 6000 watt AIMS with surge capacity of 18,000 watts (I don't intend to test or wire for that). I have tested the system with both the AC and a toaster oven running--no problem, didn't even dim the lights when the AC started. The AC load I consider less schedulable than the oven. I can decide not to cook but my wife is going to insist on a reasonable temperature. My AC is actually a heat pump with a resistance heater strip as well for extreme low temperatures that I am unlikely to encounter. I live in Maui in the winter. The heat pump feature works very well. Like others, I power all outlets and accessories from the inverter using the built-in transfer switch which transfers on shore power loss in a few milliseconds, acting as an uninterruptable power supply for the entire system. Nothing glitches when I pull the plug, even with the AC running. I also have a transfer switch on my generator to prevent back powering the grid from the genset. The only priority is shore power--if it's available neither inverter nor generator is connected. The generator disconnect is also necessary to prevent connecting the generator to the inverter output, they wouldn't be happy trying to synchronize.
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