Run Fridge off Starter Batts?

[luvrbus]

How about a little help on how to use our rigs BW batteries are batteries what ever you take out you put back I don't care what size of battery bank you have and these inverters and new chargers are going to do it their way.
I am not one for the power pole so the juice has to come from somewhere in my case it was the generator.
The way we use or coach total electric was the biggest mistake I made in the process IMHO


good luck

[buswarrior]

easy there... I was referencing the folks who were running their generators all day in Arizona, not you, my esteemed and learned busnut buddy!!!

happy coaching!
buswarrior

[Lin]

I think I may have heard this debate before.  There are good points all around.  For many, there type of use will dictate what is best.  For others, like myself, it could go either way.  I see the benefit of propane for cooking and heating first off.  Diesel heat is great if you want to spend for it.  Requiring the generator to cook seems a burden to me though.  I like being able to run the frig on propane but could do without it too.  We presently have an RV frig.  If that died, I might just go with an equal size electric because of the large difference in price.  I have done that before and managed fine.

The issue of bridge/tunnel restrictions is an important.  Here is a list from Woodalls:

LP-GAS PROHIBITED:

Maryland/Baltimore: Baltimore Harbor and Fort McHenry (I-95) tunnels. Alternate route for RVs with propane over the Francis Scott Key Bridge is I-695.

Massachusetts/Boston Harbor: All.

New York/East River: Between Manhattan and Brooklyn: Brooklyn Battery Tunnel. Between Manhattan and Queens: Queens Midtown Tunnel.

New York and New Jersey/Hudson River: Between Manhattan and Jersey City: Holland Tunnel. Between Manhattan and Fort Lee: Lower level George Washington Bridge (I-95 South) and George Washington Bridge Expressway. Lower level Verrazano Narrows Bridge. Between Manhattan and Weehawken: Lincoln Tunnel.

LP-GAS RESTRICTIONS:

Virginia/Chesapeake Bay Bridge/Tunnel: RVs equipped with ICC-approved compressed cooking tanks not exceeding two 45-pound capacity tanks (or two permanently mounted containers with maximum total capacity of 200 pounds) may cross the facility provided that, in the opinion of the toll collector or police sergeant after inspection, the tanks are completely shut off and securely attached.

Texas/Houston Ship Channel: Washburn Tunnel between Pasadena and Galena Park: Maximum of two 71Ú2-gallon containers (30 pounds gas each) or one 10-gallon container (40 pounds gas) of DOT (ICC)-approved type, with shutoff valve at discharge opening. Valve must be closed when in tunnel. LP-gas as vehicle fuel prohibited. 71Ú2-gallon containers (30 pounds gas each) or one 10-gallon container (40 pounds gas) of DOT (ICC)-approved type, with shutoff valve at discharge opening. Valve must be closed when in tunnel. LP-gas as vehicle fuel prohibited.
 

[gus]

Nellie,

You can maintain your frig with 12V if it is really cold when you drop AC power, but barely. In hot weather it won't keep the freezer temp properly.

My Norcold requires 12v DC even when on AC or LP, it operates the electronics.

The sooner you get LP hooked up the better, it works great going down the road and when you have no AC.

Also, be sure to follow very closely the dimensions for the vent duct behind the frig. It is supposed to be pretty shallow. In mild weather it may not be a problem, but in very hot weather the rear coils won't get enough cooling air.

One other point, until you add to your two sticks of butter, fill your freezer and frig compartments with jugs full of water (Or beer or wine, whatever, as long as it is liquid!). This keeps the frige temps stable and saves a lot of energy once the liquid is cooled. The most expensive thing to cool in a frig is air.

[PCC]

I am not one for the power pole so the juice has to come from somewhere in my case it was the generator.
The way we use or coach total electric was the biggest mistake I made in the process

Are you saying that to be all electric was a big mistake?

Can you offer some reasoning, because I will not install gas because of the restrictions in so many places I travel. Also because it will be difficult to install tanks, etc. without messing up my underside layout.

Keith
PCC

[Nellie Wilson]

A sight I might prefer to be spared:

(From BW): ...you'll find me walking, slowly, wearing only a thong, hands in the air...

Though who knows... might be sorta cute?

But BW, what's this supposed to mean?

Nellie, install that fridge properly and stop screwing around...

Not to be thin-skinned, but didn't realize I appeared to be "screwing around." Thanks for the thought.

Lin: Thanks for that precise info. Doubt I'd ever venture into such places, but your post is sure worth a 'just in case' printout.

Gus: Thanks for the benefit of your 12v experience... seems like most everybody concurs. Think I'll just by-pass batts as a power source (unless in some emergency). BTW, since you have a Norcold, do you know where that DC heater wire connects to? The schematic shows a 30 amp (automotive) fuse, but no such animal on my fridge. Maybe I'm supposed to install an in-line fuse?

Or is it even necessary if I don't use 12v power supply? (My AC heater is hooked up per the Norcold manual).

Thanks again to all,

Nellie

[bevans6]

You're supposed to install a fuse on the DC power supply.  To be honest, I didn't know the Norcold (what I have as well) would actually work on just AC, with no 12 vdc to run the computer, but who knows, if yours is working, it's working, bottom line.  A lot of people use a DC distribution panel set up with a dozen or so automotive fuses as the centre of their coach DC system.  I ran 10 ga. wires back to there, not because I plan on running the fridge on 12 vdc as I don't have on-the-road charging of my house batteries yet, but because I couldn't guarantee that the fridge wouldn't ever get stuck on trying to run from 12 vdc for a short period of time - the computer controls include an automatic power source function, and if there is no AC supply and the propane runs out, it might switch to 12 volt even if I didn't want it to.  So I wired it to allow 12 volt operation even if I don't plan to use it.  Anyway, it draws 15 amps on 12 volt, and  is supposed to be fused for 30 amps.  On mine the connections are two 1/4" spade terminals on the controller board on the back of the fridge.   If you know the model number of your fridge the manuals are pretty much available on line, useful for things like maintenance and error codes and such.

My vent is from the luggage bay up the back, over the top, and up to the roof about 24" in from the side of the bus.  It's important to construct that vent so that it's quite air-tight to the inside of the bus, to keep combustion byproducts out if running on propane, and the whole ammonia thing that Sean points out.  It is perfectly acceptable to route your other vents there as well, as far as I can see.

BTW my little riff on the costs of electric vs RV wasn't supposed to show any bias, I just wondered what the start-up cost of each route was, buying retail and starting from nothing.  Obviously there are other advantages and ways to go about it, including getting a fridge when you bought your bus, which is what I did.  If I was starting from scratch I would almost certainly go all electric, I think, but the cost of the inverter and battery bank to support that in a meaningful way is still a pretty major hurdle.  But I think the costs get built into the over-all cost of the conversion and there are indeed other  benefits to increasing the flexibility of your power sourcing.

Brian

[Tenor]

Nellie,
Do you have an inverter or plan to have one?  I use my inverter to run the fridge while going down the road. (mine only runs on AC or Propane).  When I'm parked with AC, that's what I use.  When I'm dry camping, I use the Propane.  Works GREAT! 

For venting through the side of the bus, I was able to carefully remove the skin of the bus only.  I looked carefully at the bus structure from the manual, checked the rivet patterns and it worked great.  I did a lot of thinking in general about where to put appliances (furnaces, water heaters,..) to really do as little cutting to structural pieces.  Good luck!


Glenn

[Christyhicks]

Boy, Nellie, you've gotten a lot of responses, and LOTS of opinions.  I guess I could tell you my thoughts and add to the confusion .

If you use the rv style fridge, they ARE expensive, but often you have three choices for operation, 12v when running down the road, a/c when you have a good source of electric, and LP when you want to boondock for extended periods of time.  Each one has limitations, the 12v sucks batteries down and cools the least, a/c cools better but needs power, and the lp eventually will deplete a smaller propane tank in about two months, although it cools the best.  The advantages of rv fridges are that they are designed for our application, a moving vehicle, multiple sources of energy, door locks, mounting brackets, etc.

When installing an rv fridge, read the installation directions and clearances carefully.  The sides are often 0" clearance and normally, the rear clearance from the wall to the coil is often 1/2"-1". The top rear of the fridge should be baffled or sealed flush with the back of the fridge, if you can visualize this:  the air should enter from the outside grill, just below the bottom of the coil on the back of the fridge.  The fresh air should be forced to channel up through the bottom of the coil and on up between the coil loop, existing through the finned condenser at the top, and out the roof, with no place else for it to spread.  Often, people add a small kilson thermostat to the condenser fins and add a small computer style 12v muffin fan to force the air to follow this path, or at least to "blow" air across the condenser.  The fan shuld not be necessary on a properly installed fridge, but even the fridge manufacturers are recognising that very few fridges are installed properly.

The disadvantages of rv fridges are that the fridge needs to be "relatively" level when operated, they are pricey, and certain ones have had problems with the elctronic controller boards, hence the production of "dinosaur boards", which is a board you can buy for pretty much any rv fridge that seems to be more durable, as per anecdotal info available.

Many people swear by a/c fridges, and they are truly less expensive and seem to control inside temps better.  Many people operate them on total electric buses with good battery banks and either run solar panels and/or generators to replace the energy used.

Disadvantages are that it is much harder to properly mount a home fridge, you are tied to ONE source of energy and if you have a problem with your electric system, you're pretty much going to be buying a cooler and ice until you get it solved.  The home style refrigerators are not "approved" for mobile installation, not that I've heard of this being an issue for most people.

As for venting, even the freon used in home style refrigerators is dangerous, and if parked in warm areas, if you don't have ventilation, you will increase the amount of heat inside the coach.  A condenser needs to reject heat and it has to go somewhere, facts are facts.

For us, we've had rv's for a lot of years, and recently purchased a Prevost with inverters, big battery banks, and solar panels, but I will keep my propane.  I'm a redundant type of gal and I like having choices. . . if I have a problem with the lp, I can run on electric, if I have an inverter go down, I can run on LP. . . I just like having choices.  Having worked on plumbing and hvac for quite a few years, I have no more fear from LP than I do from electric, each has it's dangers and each can start a fire.  Personally, I find a propane system to be pretty simple, not a lot going on there, not a lot of components in line to fail, etc., and lots of energy output.

When making decisions on your coach, keep an open mind, learn all that you can, listen to all opinions, and decide what works best for you.  But, also remember that often, the reason you see the majority of people going in a certain direction, is that it's the most sensible for a wide variety of applications.  There's nothing wrong with choose a simple path. . . you're not out to impress anyone, you're just building your bus to serve your needs.  Good luck, and remember, ymmv, Christy Hicks

[buswarrior]

screwing around = installing in stages

The brevity of the short last bit required a delivery that is impossible to convey in the written word.

I will refrain from attempts at comedy.

happy coaching!
buswarrior

[Nellie Wilson]

From BW: I will refrain from attempts at comedy.

BW: Please don't!  Blame my misunderstanding on my limited translation skills. You've given me some great tips - and I've had a lot of yucks, 'thongs' to you . And, actually, I agree with your assessmnet... but I'm stuck having to do things in stages. Traveling and living in this thing, and fitting it out on the road takes some juggling. Usually complicated by putting out one mechanical 'fire' or another.

Christy: Thanks for the specifics. I've got the 0" side clearances established but the coils / condensor are 8" from the outside wall (due to head room and roof curvature restrictions). Too much? I can change that, but only with a major re-design.

Tenor: Yup, got a little 1000 watt (continuous) inverter (out of an 18-wheeler). Not that it matters, seeing as I have no batteries to run it on .

Bevans: Pardon my poor explanation. I do have 12v power running the fridge computer. I just can't figure out the hookup for the 12v fridge heater.

Thanks again to all.

Nellie

[John316]

Nellie,

FWIW, we have a regular AC house fridge. We are all electric. We have a generator, and a bank of 6 8D gel batteries. We usually go about two days, before we need a charge. We will hook up our alternator to the inverters, that way we can charge as we drive. But that will happen in the future.

God bless,

John

[bevans6]

Nellie:  Bevans: Pardon my poor explanation. I do have 12v power running the fridge computer. I just can't figure out the hookup for the 12v fridge heater.

It's the same connection on my Norcold 841, there is only one 12vdc connection for both the computer and the heater.  The fridge figures out how to get it to the heater.  That's why I wired it with a 30 amp fuse and the 10 gauge wiring - it could decide to pull 15 amps and run on the 12vdc heater for some oddball reason, and I wanted to have the wire and the fuse in case it did.  Maybe your fridge controls things differently, but mine has an auto mode where it searches for a power source.  If there is nothing else, it will try the 12 volt source.

edit: I have a soft copy of the manual for the n600 and n800 models.  It has wiring instructions and venting installation diagrams, dimensions, all of that.  I can email it to you if you like, just ask.


Brian

[Christyhicks]

Temporarily, you can fashion an air dam from the outside in, but lifting the vent access panel (if you have one), and cut a piece of sheet metal (I used a cookie sheet one time) that blocks the air from the top of the door opening across to the bottom of the condenser coil on the back of the fridge. .  (you want the air to NOT be able to get up between the outside wall and the outside edge of the coil on the back). . . when I did it, mine was foil taped to the inside top of the door opening and angled up and leaned against the bottom of the condenser coil and was again foil taped to that tube, until I could do a better blockout.

Later, if you have to pull the fridge, you simple build a baffle or box against the outside wall that allows you between 1/2"-1" clearance between the coil and the wall on the back.  I would strongly advise that this box have a sheetmetal covering, JUST IN CASE you get a leak somewhere on the pilot assembly and get a nasty flame trying to come out where it shouldn't. . . . most of the time, there's all kinds of wood around those fridges, but I like to line with sheetmetal whenever I can just for EXTRA safety. 

Actually, I've seen WAY more coaches with gaps like yours in the back than I have seen installed properly. . . and this is from major coach manufacturers.  I was pleasantly suprised to see baffles on the sides and tops of ours in this Beaver conversion, even though they STILL had way too much space behind it.  If there's too much space behind the coil, the air can waffle around behind it and up through the roof vent, instead of being forced inside the loop formed by the coil and up through the fins at the top.  Does this make sense or am I just too obtuse. . . it's hard for me to explain it properly so you can picture it, I'm afraid.

Well, back to my paperwork. . . today is a "working" day , so that we can play tomorrow, ha ha.  Christy Hicks

[luvrbus]

There you go guys John 316 said it

3000.00 dollar battery bank
6000.00 worth of inverters
12,000.00 generator  
If you are going to have a total electric coach that is the way you do it he did not mention run time a wild guess 5 to 6 hrs to bring the batteries back to full charge,I have the tee shirt



good luck