AC Electric Only Skoolie?

MingDynasty · 10-22-2019, 01:56 PM

Hello everyone,
Just joined the forum here. I have a 2008 International and am preparing for the conversion.

I'm wondering if I'm missing something important here. I'm thinking about running all my electric for AC. The two power sources would be shore power when I am camping and generator for anytime I am not camping (traveling down the road, walmart parking lot). I have a 6500 watt generator I plan to install.

I'm planning on using house window units for the air conditioning (the bus does not currently have air conditioning) and regular 115v appliances for the kitchen.
If I stick with an AC electrical system only, what benefits will I be missing from a 12v system with batteries? It seems most people have a 12v system, too, so I'm wondering what I'm missing if I stick with a 115v system only?
Any help for this rookie is appreciated!

MambaJack · 10-22-2019, 03:15 PM

I think it would be a fine way to go if you were okay with zero electric if not plugged into shore or generator, However if you want say a light on when not plugged in battery and a dc light is a great way to go

Booyah45828 · 10-22-2019, 03:19 PM

You're not missing anything. For simplicity's sake, you don't have to have any sort of house battery bank.

I ran 2 window units in the back of mine for 2 years. Had them surrounded by 1/2 osb, ran extension cords out through a hole in the osb and to the generator.

I got tired of removing the ac units and installing windows after we were done camping so I installed a rooftop ac unit. I ran 2 wire romex for it into the bus ceiling, down towards the wire loom in the wall, and towards the back where we ran it out the emergency exit door.

Did that for 2 more years and we eventually wore a hole in the romex from where the door shut on it.

So I cut a hole in the side of the bus, ran the romex to that, and mounted one of these puppies

https://www.amazon.com/Hubbell-Bell-...25423961&psc=1

And that's how it's been for the last few years. I run an extension cord to this from either shore power, a friend's generator, or the on board generator under the bus.

Works fine for me, and unless you plan on having a fridge, I don't see a need for a house battery bank/solar. Truthfully, most camper's don't have one, they just use the 12v battery for certain lights and control circuits. They use either propane, or 120 vac for all the actual power stuff.

o1marc · 10-22-2019, 03:45 PM

You'll be missing the quiet solitude of no gennerator running.

TheHubbardBus · 10-22-2019, 03:49 PM

Just to clarify, a battery-storage system does not have to be 12V, nor do the appliances you might run directly off of battery storage.

I've used the word storage two times, because that's basically the difference between what you're considering and what other people might be using. Storage. With a generator alone, your energy storage is in the form of the fuel you carry to power it. With a battery-based system, at least a portion of your storage is... batteries.

With a battery-based system, it makes sense to utilize as many DC-powered appliances as possible, 12V or otherwise, in order to avoid the efficiency loss inherent in converting DC from your batteries to AC. With generator/shore-only, which are natively AC, no such losses would occur.

Some appliances meant for off-grid / rv living that are DC are more efficient that AC counterparts, but that's not necessarily because they're DC. It's more the fact that because such applications imply battery storage most of the time, DC would make the most sense.

One potential concern regarding your generator, with the caveat I don't have practical experience 'Walmart camping'... would it be loud, and if so, would that shorten your welcome?

MambaJack · 10-22-2019, 03:55 PM

Quote:

Originally Posted by TheHubbardBus

Just to clarify, a battery-storage system does not have to be 12V, nor do the appliances you might run directly off of battery storage.

I've used the word storage two times, because that's basically the difference between what you're considering and what other people might be using. Storage. With a generator alone, your energy storage is in the form of the fuel you carry to power it. With a battery-based system, at least a portion of your storage is... batteries.

With a battery-based system, it makes sense to utilize as many DC-powered appliances as possible, 12V or otherwise, in order to avoid the efficiency loss inherent in converting DC from your batteries to AC. With generator/shore-only, which are natively AC, no such losses would occur.

Some appliances meant for off-grid / rv living that are DC are more efficient that AC counterparts, but that's not necessarily because they're DC. It's more the fact that because such applications imply battery storage most of the time, DC would make the most sense.

One potential concern regarding your generator, with the caveat I don't have practical experience 'Walmart camping'... would it be loud, and if so, would that shorten your welcome?

Hubbard, i changed 12v to dc in my post to avoid the confusion,
Also, i don't think efficiency is that big of an issue if you are running off a generator or shore, compared to solar of any voltage of battery

TheHubbardBus · 10-22-2019, 04:05 PM

Quote:

Originally Posted by MambaJack

Also, i don't think efficiency is that big of an issue if you are running off a generator or shore, compared to solar of any voltage of battery

Guess that depends on your use & circumstance. If you're charged by your usage efficiency might matter to you. Plus fuel costs money. Or maybe the amount of fuel you can carry is what determines how long you can stay in the woods?

But yeah, I agree... certainly much less of a concern than solar in most cases.

MingDynasty · 10-22-2019, 05:38 PM

Thanks for the reply! I was planning on using AC powered mini fridge/freezer unit (sold at box stores). I was going to just let the generator run while driving down the road to keep the fridge running.
I thought purchasing two mini fridge/freezer units was more economical than purchasing an RV fridge.

Iqinsanity · 10-22-2019, 11:13 PM

You will lose all your clock settings and things like that. You also lose all electricity not immediately consumed so it’s far more expensive in the long run. There’s a reason it’s called a battery “bank”.

If you really want to run a generator with no battery I would highly recommend the smallest generator you can get that will still run the highest consuming device. You will have to constantly swap what’s on and what’s not but running a 6500w generator to power a 150w tv and nothing else will get expensive fast. It will still consume a lot of gas whether it’s got a small load or a medium one.

JDOnTheGo · 10-23-2019, 05:48 AM

Quote:

Originally Posted by MingDynasty

If I stick with an AC electrical system only, what benefits will I be missing from a 12v system with batteries? It seems most people have a 12v system, too, so I'm wondering what I'm missing if I stick with a 115v system only?

Convenience is the answer. (IMO)

What is your 'mission'?? Do you plan to live in your rig or use it once a month to go fishing for a weekend?? What 'creature comforts' do you plan to have (running water, shower, fan, refrigerator, TV...)? Do you plan to always be at an RV park with shore power? (no boondocking?)

This is a good example of why a bit of time in an RV/motorhome will pay big dividends in figuring out/knowing what your conversion needs are.

If your mission is much more than occasional weekend camping trips, it is my opinion that not having a house battery bank is bad choice. Every mission/lifestyle is different, of course, but typical use includes a large number of electrical devices. Things like water pump, lights, fans, refrigerator, computer, television, microwave, etc... Even an absorption refrigerator requires a bit of electrical power to operate. Having to start a generator just to brush your teeth or flush the toilet is not a good plan (IMO).

Common courtesy and the rule in many places, is that running a generator at night is not allowed (some exceptions, of course). That leaves you without electrical all night (think lights, fan, watching TV, running a CPAP, etc...).

I admit to being strange, but I find generators to be nearly criminal. Yeah, just an opinion, I know. The noise and vibration drives me insane. Of course, there are loud generators (open frame, construction style) and less noisy generators (inverter style). IMO, there is no "quiet generator". I've stayed in some really fantastic and remote places that were ruined (for me) by the guy a half mile away running his generator. Once a guy with a Honda 2000 was parked about 500' away and I had to move. All that said, you might love the sound of the thing but I bet you will come to dislike it if you have to run it every time you want a bit of power.

I occasionally see some folks surprised at the cost of running a generator. They just barely sip fuel, right? Well... not exactly. Way back in 2016 I wrote this blog post - the part about the cost of running a generator might be useful to you.

All that said, I'm sure a setup could be created that requires nearly no electrical power and some would be happy with that type of living. (like gravity water system, propane stove/oven, ice chest for food, etc.). I will call that lacking many modern conveniences but that reeks of opinion and I certainly don't feel that "modern" is automatically "better". Maybe even using a large-ish water pressure tank so you can brush your teeth/get a glass of water/start a pot of coffee/flush the toilet without needing the water pump.

If the concern/fear is cost, you may be reading too many of these threads about people trying to do a huge amount from battery. A small/basic DC electrical system does not have to be expensive or complex. A couple 6VDC batteries, a charger, and fuse/distribution panel. Probably not more than $300.

MingDynasty · 10-23-2019, 05:59 AM

Thanks for the feedback. I was thinking I would only use it at RV campgrounds with shorepower, but as you state it may be near sighted to think that is all I'll ever use it for. I'm starting to think it will be worth it to add even a simple DC battery system, too.

MingDynasty · 10-23-2019, 06:05 AM

Thanks. Good point! The cost to run a generator just for a few small items can add up quickly.

cadillackid · 10-23-2019, 06:06 AM

ultimately id want the versatility of being able to run on whats available... seems if the OP isnt planning on boondocking then his setup would be OK if its always shore powered..

(plenty of commercially available trailers and motorhomes were built without anything but simple 12 volt systems for some lights and maybe a roof fan or such)..

the A/C - I got news for the OP. dont expect your window A/C to cool you while driving down the road.. if running the genny to keep the A/C cold is your desire .. you will be disappointed..

if you just need to keep the refrigerator cold.. I would likely look into a high capacity alternator(your bus may already have this piece) and an inverter.. that will keep your frig cold and can charge a house battery or 2 that can be used for interior lighting and charging phones, etc if you arent connected to ashore power..

I know of people who never do anything but go to full-service campgrounds.. a setup like you talk of is fine for this.. no generator noise and no need for elaborate solar or super expensive battery setups.

-Christopher

MingDynasty · 10-23-2019, 06:42 AM

Quote:

Originally Posted by cadillackid

the A/C - I got news for the OP. dont expect your window A/C to cool you while driving down the road.. if running the genny to keep the A/C cold is your desire .. you will be disappointed..

-Christopher

Thanks Christopher for the input. I was going to install two window units. You don't think that will cool the bus? What would you suggest for A/C?
Thanks!

Sehnsucht · 10-23-2019, 07:13 AM

Quote:

Originally Posted by MingDynasty

Thanks Christopher for the input. I was going to install two window units. You don't think that will cool the bus? What would you suggest for A/C?
Thanks!

Yes, I'm curious as well. Is the assertion that a 110V window-style AC unit powered by a generator sufficient when parked but not for going down the road? Or rather it just that it is too much to expect a single AC unit to be able to cool the entire bus and adding multiple AC units multiplies the generator demands? I have often contemplated this conundrum myself because it almost seems like you'd end up needing two AC systems, one driven by the engine one another powered by the generator or shore power.

Scaling down the problem, in modern semi trucks you can get them with a battery-powered AC unit for when parked that cools the sleeper bunk and 4 batteries are sufficient for a full night's comfort in all but the most brutally hot climates. The batteries are recharged daily while driving and they are separate from the engine-starting batteries. If the convenience batteries prove insufficient, the engine can even restart itself to recharge them. I would love to scale up this type of system for a bus.

rffffffff · 10-23-2019, 07:18 AM

Quote:

Originally Posted by MingDynasty

Thanks. Good point! The cost to run a generator just for a few small items can add up quickly.

I think this is the biggest thing. My Honda generator 2200w will go through $3 of gas in 8 hours powering just a fridge, basically idling. $9/day, $270/mo for generator alone and that’s an efficient one. A 6500w non inverter generator could be 5 or 10 times the cost to run.

cadillackid · 10-23-2019, 07:21 AM

Correct , for driving it won’t do a thing , for being parked your 2 window units (depending on size) will be fine. Assuming you are insulating the bus or mainly using them in shaded areas or at night.

As I’ve mentioned before, driving down the road takes a LOT of A/C

Booyah45828 · 10-23-2019, 07:49 AM

We burned through approximately 60 bucks of gas in my scenario running the generator at night powering both ac units over a 4 day period.

I don't have a fridge, and use 2 yeti style coolers for food/beer.

We only do this bus trip once per year. 2-3 times per year we'll use it for a one night trip where will use only about 20 bucks of gas.

The rest of the time I either have access to shore power or it's comfortable enough outside that you don't need Air Conditioning.

As far as power for tv/microwave/coffee pot/water pump/etc. I have none of those, so I don't need power for them. The only thing I do need power for is charging a handfull of cell phones, which is done by the cigar lighter on the bus batteries.

In my scenario(steel tent) it wouldn't make sense to spend $$$$ on LiFePo batteries and solar panels, when I can typically provide my electric needs for 100 bucks per year or less. I'd love to do such a thing, but it's not economically sensible.

Iqinsanity · 10-23-2019, 08:18 AM

That’s the million dollar question.

Is this a couple time a year camping trip or you primary or secondary residence.

PNW_Steve · 10-23-2019, 08:29 AM

I have a travel trailer that was generator/shore power dependant. I did have propane for cooking and hot water.

I finally added 300 watts of solar on the roof. I still have to run the generator some but not nearly as much as before.

Silence is golden!

A note on generator selection. The Honda, Yamaha and Champion inverter generators are pretty quiet. Open frame "contractor " generators are generally quite loud..

On a trip to Little Goose Landing recently I was sitting outside having coffee. My Honda was sitting about 15 feet away running. I could not hear my Honda over the racket that another campers open frame generator that was a good 200 yards away. For three days and nights we put up with it in hopes that they would leave. No such luck. We gave up and headed for the mountains.

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