AC or DC? 😱

[Hippiehustlin]

Hello everyone!

My girlfriend and I recently purchased a 1997 Thomas flat nose and are getting our conversion underway. It’s about the time to start roughing in my electrical system. I have a lot of experience with AC current as an electrician and I’m leaning towards running everything at 110v.

I’ve had some people say that there is a considerable loss of output having to invert from DC to AC, but, since I do have the AC experience I’m leaning that direction. Does anyone have any experience to shed some light on the pros/cons?

I’m planning on having the solar charge my battery bank and run everything off of an inverter. I do, however, know that some appliances will run more efficiently off of DC since I won’t have any 220v without being a little creative. Any input is appreciated!

Thank you in advance!
IG: @hippie_hustlin_bus
@boerseunbiltong

 

[Johnny Mullet]

My bus is all 12V except the 10.1 cu ft fridge running off a 1500 watt pure sine inverter. All my lights, water pump, TV, stereo, fans, etc are all 12V. I only have (2) 100 watt solar panels charging (2) 6V golf cart batteries wired in series giving me 12V and 235 amp hr. I do not have a generator and only "plug in" I have is a cord for my fridge when parked at home. I have camped and boondocked many times and had no problems except on our maiden voyage when the fridge door came open on an hour ride depleting my batteries, but they recovered the next day no problem.

Running everything 110V is going to require lots of solar, lots of batteries, and a huge inverter, but that is how some do it and it seems to work for them. Good luck!

 

[Hippiehustlin]

Thank you Johnny. Everything seems to work just as efficiently on DC?

It’s def going to require A LOT more solar and a much bigger battery bank. One of my bigger reasons for sing 110 was because we’ll spend half our time boondocking and the rest on shore power. But, I guess we could always invert to DC for those times on shore power.

 

[roach711]

Inverting from DC to AC will cost you 10 - 15% of your power depending on the efficiency of the inverter. Converting AC to DC also burns some energy but when you're plugged into unlimited shore power it's really not a concern.



Most boondockers opt for rather minimalist electrical consumption. Solar will help extend your battery power but remember that you have to park in the sun to keep those watts flowing. Depending on what part of the country you're in that can make for a hot bus in the summer.



Propane stoves and heating will save a lot of battery power. Any resistance heat will suck down a battery bank in a hurry.



All of our lighting is DC LED. The water pump, furnace fan and vent fan are all DC. The water heater is AC and/or propane and our cooktop is propane. DC televisions are available.

 

[mmime]

going from a
DC to AC incurs a cost, but there are ways to temper it

12v to ac not as efficient as going from 24v to ac which is not as efficient as going from 48v to ac

get your lith ions in proper orientation to tally up to 48v, most efficient of the lot

keep your inverter as close as possible to the batteries

use proper sized cabling

 

[JDOnTheGo]

You are in luck!! DC is incredibly simple compared to AC. Google the difference and I bet you'll be up to speed in an hour or two.

You'll have to decide how you want your rig to operate. We are all different and have different missions. My coach is all electric (from solar), the next one is anything but electric. Nothing wrong with either approach.

It is unlikely you'll need 220VAC. Obviously, there are some appliances that will use it but they often have a 110VAC alternative.

 

[Booyah45828]

If boondocking was my ultimate goal. I'd do something similar to johnny mullet. Most of your little uses like fans, pumps, lights and electronics have dc powered options available. Heck, most of those items (except for motors of course) usually convert the ac to dc internally anyways.

So if you can avoid the 10-15% loss creating the AC, you're power ahead. I also imagine there is an energy loss converting the AC back to dc for use in the devices (no conversion is ever 100% efficient). So the total loss of conversion back and forth might be more.

Use an Inverter for your electrical needs that can't be sourced at 12v easily/economically (fridge,freezer,washer,microwave,coffee maker,etc.).

Any of your large heat producing items(water heater, stove/oven, drier, furnace) run off propane.

As far as air conditioning goes, I don't think it can be operated off a reasonably priced battery/solar setup. So maybe have a generator onboard for when it is necessary.

And before anybody flames me on that, you can buy a pretty nice generator and a large amount of fuel for what some of you have in your solar setups.

Or just be connected to shore power on the really hot days :biggrin:

 

[Tango-SKO]

Given my desire for redundancy...I plan on some solar, a small-ish battery bank (450ah), mostly DC, light AC (mostly when docked) and a small genny to back everything up...and ...a little propane just to keep Hank Hill in business.

 

[brokedown-SKO]

Here's a post from someone else asking some basics regarding DC+solar with some opinions on things to run from it: http://www.skoolie.net/forums/f9/solar-help-raleigh-nc-please-23580.html#post282567