Generator: Diesel vs LP (Propane)

smiller

2008 View J (2007 NCV3 3500)
The benefit is that it runs off of the Sprinter fuel tank so it will run much longer than the propane generator.
But again, that depends. My vehicle (a Winnebago View) carries an 18-gallon propane tank. A diesel generator would be able to use perhaps 3/4 of the main fuel tank (the fuel pickup on almost all vehicles with factory diesel generators is situated so that you can't run the main tank below 1/4), so my 26 gallon main diesel tank would yield about 19 gallons usable fuel, so not much difference there vs. propane. Even with equivalent fuel the diesel would run a bit longer because it consumes slightly less fuel per hour, but still that doesn't equate to any real significant difference in run time vs. propane. The equation begins to greatly favor the diesel in larger vehicles with larger main tanks, but in the Sprinter... not so much...
 
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IslandGuy

New member
But again, that depends. My vehicle (a Winnebago View) carries an 18-gallon propane tank. A diesel generator would be able to use perhaps 3/4 of the main fuel tank (the fuel pickup on almost all vehicles with factory diesel generators is situated so that you can't run the main tank below 1/4), so my 26 gallon main diesel tank would yield about 19 gallons usable fuel, so not much difference there vs. propane. Even with equivalent fuel the diesel would run a bit longer because it consumes slightly less fuel per hour, but still that doesn't equate to any real significant difference in run time vs. propane. The equation begins to greatly favor the diesel in larger vehicles with larger main tanks, but in the Sprinter... not so much...
Last time I checked the stats of the Onan propane and diesel generators:

Full load 0.7 gal @hr (propane) vs 0.4 gal @hr (diesel)
Half load 0.6 gal @hr (propane) vs 0.3 gal @hr (diesel)

Your year View has the 18 gallon tank (actually 14.4 gal useable). I believe starting in 2010 the tanks were moved inboard which limited the size to 13 gallons (10.4 gal useable)


If we use your example of 19 gallons of diesel/0.4 gal = 47.5 hrs of run time
vs 14.4 gallons of propane/0.7 gal = 20.6 hrs of run time

That is a pretty significant difference in run time!

Jim
 
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IslandGuy

New member
I am in the same boat (my original equipment '45 amp' Parallax charger can only supply about 10 amps at best at its single preset charging voltage) so this weekend I am installing a dedicated Iota 55-amp 3-stage charger. This should provide enough current to bring the batteries back up in an hour or two of generator run time, depending on state of charge. It really isn't practical to use most OEM-supplied converters for this purpose, they are just too slow.
Good move....your batteries will be much happier!

Jim
 

smiller

2008 View J (2007 NCV3 3500)
Last time I checked the stats of the Onan propane and diesel generators ...
When comparing fuel consumption you also need to also take into account that the diesel gen model being compared is making less power at 1/2 and full load than the propane. And naturally, if you substitute a smaller propane tank in the example than propane run time will be less, just as with a larger tank run time would be more. But you are correct in that I neglected to consider that only 80% of the propane tank capacity is usable, and that extra 4 gallons does give several extra hours to the diesel.

I guess the best way of putting it would be that one should do the math for their particular vehicle and consider their own needs, then decide whether whatever additional runtime is worth an extra $4k. To some it might be, but I suspect that most will not require the extra runtime often enough (if at all) to justify the investment. But as always, YMMV (or in this case, YRMV :D: )
 

Mein Sprinter

Known member
Plus, the diesel gensets hang significantly lower, do they not?
Maybe so but the propane gen's exhaust hangs pretty low on my RT SS Agile.



As for being quiet: forget it it, is very noisy and needs something to be silenced. Wall insulation might help; better muffler than what is available currently.

We just came back from a 7,447 mile snowbird trip and used the propane gen generously. Never a problem but we hate turning it on like I said...it's noisy > disturbing campers and wild life when dry camping.

cheers....
 

IslandGuy

New member
When comparing fuel consumption you also need to also take into account that the diesel gen model being compared is making less power at 1/2 and full load than the propane. And naturally, if you substitute a smaller propane tank in the example than propane run time will be less, just as with a larger tank run time would be more. But you are correct in that I neglected to consider that only 80% of the propane tank capacity is usable, and that extra 4 gallons does give several extra hours to the diesel.

I guess the best way of putting it would be that one should do the math for their particular vehicle and consider their own needs, then decide whether whatever additional runtime is worth an extra $4k. To some it might be, but I suspect that most will not require the extra runtime often enough (if at all) to justify the investment. But as always, YMMV (or in this case, YRMV :D: )
I will go back to my main point of this discussion. With a Sprinter based motorhome you have a 26 gallon fuel tank with ~ 3/4 of that which can be used for the diesel generator vs a smaller capacity propane tank....you have a significant difference in how long each generator, that is available in these Motorhomes, will run.
If you plan on using your generator for extended period of time (A/C) then you are probably better off with the diesel configuration...in a Sprinter motorhome...but you have to pony up much more $$$

Jim
 

Francois

Member
Last time I checked the stats of the Onan propane and diesel generators:

Full load 0.7 gal @hr (propane) vs 0.4 gal @hr (diesel)
Half load 0.6 gal @hr (propane) vs 0.3 gal @hr (diesel)

Your year View has the 18 gallon tank (actually 14.4 gal useable). I believe starting in 2010 the tanks were moved inboard which limited the size to 13 gallons (10.4 gal useable)


If we use your example of 19 gallons of diesel/0.4 gal = 47.5 hrs of run time
vs 14.4 gallons of propane/0.7 gal = 20.6 hrs of run time

That is a pretty significant difference in run time!

Jim
This is why I choose diesel; predominant style is off grid, furnace-frig-hot water-cooking are already consuming propane, if you have to run the genset on propane also for AC and recharging batteries = overall not much time available,
 
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smiller

2008 View J (2007 NCV3 3500)
Propane usage for cooking, fridge, etc. is generally pretty low. And with diesel you also have a little something competing with your generator... your vehicle engine. Comparisons assuming 19 gallons of available diesel fuel are also assuming that you will arrive at your destination with a topped-off main tank... ;)
 

Francois

Member
Propane usage for cooking, fridge, etc. is generally pretty low. And with diesel you also have a little something competing with your generator... your vehicle engine. Comparisons assuming 19 gallons of available diesel fuel are also assuming that you will arrive at your destination with a topped-off main tank... ;)
Agree... but overall you have a bit less of double fuel capacity and haft the consumption per hour with diesel, so it does translate to more time. It is also easier to find diesel vs propane in some remote places...
 
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Old Crows

Calypso 2014 View Profile
3.2D or 3.6LP...? Back in Oct, I was told the diesel was not available due to a fire at the engine build facility. This may explain the premium price. Our old Ventura had a 2.5LP... It was more than adequate and thrifty on fuel. Our VP has a 3.6LP that will run all electrics including the Mach 8 heat pump. A little more thirsty. If you look at the specs both gen sets are almost identical in fuel consumption at full load, if converted to Lbs/hr. At half power, the diesel has a slight advantage. The LP has slightly more wattage output, which may be an advantage. Sound measurements are identical at 68 db. So, the difference in "noise" may be due to the differences in combustion characteristics, rpm, vibrations. Diesels do seem to have a low frequency throb or resonance compared to a gas motor running at faster rpm, but that's my impression.

There seems to be a concern over needing to running a generator for long periods to charge depleted batteries. That's a reasonable concern... However, we should recall that we are only charging a pair or several batteries and not a battery bank found in a diesel sub. Either gen set should be able bring a healthy battery set up to a "usable" state of charge within a very short time. Usable to me means that it will have enough of its charge restored to be able to generate useful power for a reasonable amount of time. It doesn't mean that it's going to be charged and polished up to maximum effectiveness in every charging cycle. Doing that, it seems to me would be a real waste of energy when you are trying to sustain yourself for several days in the field. So it's that old story of how much effort you have to put in to charging the battery the last several % points.

I like having several options a available to me. Having a diesel genny in a diesel Sprinter seems like putting all my eggs in one basket. If I have an LP set, I at least have a second option should I need to generate power if the diesel side fails. I've already got LP aboard for the range, WH, furnace... So why not tap that source? Then there's the issue of powering the Sprinter if fuel gets low. I've got about 80 miles under ideal conditions ... Less under adverse conditions.

Then there's the diesel stink.... LP has a bit of odor but it's less objectionable...

Then there's more preventive maintenance on the diesel fuel system.
 

Peter Tourin

2020 Unity RL, ex 2012 Unity MB
One of my issues with any generator use is the noise - I personally don't mind it, but I know others do, especially at the National Parks type of campground, where lots of people are tenting or dry camping. I don't mind running it for 10 minutes every so often, but I don't like to run it for an hour or more. But suppose my house batteries are about 200 AH capacity and I've run them down to 50%. And suppose my converter will charge at 50A. And suppose I want go bring my batteries from 100AH up to at least 150 or so. That's going to be an hour of running the generator, more or less.

I wish there were easy ways to quiet the generators down. If you search, there are threads on extra mufflers and on insulating the generator compartment - but the general consensus seems to be that you can't make a big improvement.

This probably doesn't apply to anybody else, but I personally wanted an LP generator because I'm badly allergic to hydrocarbons. I wasn't willing to consider buynig a diesel RV until I tried a Sprinter last year, because diesel fumes make me pretty sick quite fast. It was a revelation to me that these rigs are so clean and odorless. Not so the diesel generator though - I can smell them pretty strongly, and they make me feel bad quicker than the smell from the LP generators do. I expect this is just me though - seems to be inherited, as other family members have it.

It does all make solar a bit more appealing! - and I'd love to do a ~200W installation - but boy, it's hard to decide to spend $2500 or so to make my neighbors happier with my quiet rig <g>... But I'll bet that after we retire and we're travelling a lot, I'll be thinking more seriously about adding it...
 
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smiller

2008 View J (2007 NCV3 3500)
Yeah, noise is always an issue. I have a Honda eu2000 inverter generator and it's reasonably quiet (or more accurately not too noisy :), but with a equal load applied I think the 3600LP is about the same. Not too bad, but still louder then I like to use in a quiet campground. What are really nice are the baffled, water-cooled, 1800-rpm generators in large Class A RVs... you can stand right next to the vehicle and all you can hear is a slight purr. But one of those would fill the back of Sprinter. :D:

On the subject of charging batteries I just installed an Iota 55-amp charger to use for off-grid charging. Right now I have a pair of Group 24 batteries in parallel (these will eventually be replaced with a pair of GC-2 golf cart batteries.) For a quick test I drew about 40 amp hours out of the batteries and turned on the charger. It went into bulk charge mode and supplied its max. output (55-56 amps) for about 30 minutes, and then as the voltage came up it went into absorption mode for the rest of the charge cycle, maybe 20 amps down to 1-2 as the batteries reached full charge. So this brought the battery bank back up to a reasonable level in about 60 minutes, and full charge in about 90. The limitation in this case is the batteries, not available charge current, as I was easily able to achieve greater than a C/5 rate in bulk mode and that's as high (or actually higher) than flooded-cell batteries should be subjected to. So... this is about as fast as it would be physically possible/safe to charge them (the charger is a little over-sized for the current application, it was purchased with the larger-capacity GC-2 batteries in mind.) So anyway, it seems that an hour or two per day of generator time ought to do it. At that rate I'd be out of water long before I was out of generator run time.
 

Peter Tourin

2020 Unity RL, ex 2012 Unity MB
I've been curious about that Iota DLS-55/IQ4. It has the higher charging voltages and would work with Fullriver batteries, but I'm not sure if it's an easy upgrade for my Parallax 7355. I understand that both Progressive Dynamics PD4655 and PowerMax Boondocker 60 would easily drop into place, but they don't have the higher voltages.
 

smiller

2008 View J (2007 NCV3 3500)
You might want to consider doing what I did which is to keep the Parallax converter and augment it with the Iota. I have the Iota connected directly to the battery bank so when I hit the battery disconnect switch (controlled by a switch and solenoid in the Winnebago) then the batteries/Iota charger are isolated, so the Iota charges the battery without having to power house loads or having the charging algorithm be confused by them. Once isolated the Parallax tales over the house loads so I have DC power there as well. During normal (on-grid) operation I just use the Parallax (although I could turn it off and use the iota if desired.) IOW I don't use them both at the same time on the same bus, the Iota charges the batteries while the Parallax powers the house.

I figured that since I already had the Parallax installed why not use it, plus I can charge the batteries faster by isolating them and dedicating the Iota to that purpose.
 
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icarus

Well-known member
Another plus for an LP is they are more tolerant of bad fuel. You very rarely (I have never heard of bad LP per se.

Icarus
 

scottpoling

New member
After purchasing our View Profile in 2012, we have had it in for service at Cummins 6 times resulting in its entire replacement in September 2015. We used the new replacement for 3 dry camping events last fall and it wasn't used since, other than monthly starts for maintenance as recommended. We took it out last month for the first time and it would not start. Took it in to Cummins and are told there is a failed spark plug harness. Not sure how that happens so soon but we are told the Warranty is assumed from the original generators purchase date and we will have to pay over a grand to have it fixed. I am now considering converting to Propane because I have no faith in the product that it will not fail again. Cummins sure hasn't assumed any responsibility and backed their product.
 

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