Lithium & 2nd Alternators Verses Onan Generators - Mike Mas

[RossWilliams]

How large is the gas tank? Will the Honda 2000 start and run AC overnight in hot weather without refueling? Also, how do you carry fuel? I am a bit leery of a gasoline tank inside the RV. It seems like fumes are inevitable as the tank heats up.

[DUTCH in Atlanta]

Originally Posted by RossWilliams

How large is the gas tank? Will the Honda 2000 start and run AC overnight in hot weather without refueling? Also, how do you carry fuel? I am a bit leery of a gasoline tank inside the RV. It seems like fumes are inevitable as the tank heats up.

A 2000 watt generator will not run a Dometic Rooftop A/C which draws about 3400 watts.

[Winetime1]

One other consideration is the generator has a limited run time and I hear they sometimes don’t perform well under load. As your a/c cycles on and off, the generator continues to run, burning fuel. The battery provides what is demanded with silence in between.

[DUTCH in Atlanta]

Originally Posted by Winetime1

One other consideration is the generator has a limited run time and I hear they sometimes don’t perform well under load. As your a/c cycles on and off, the generator continues to run, burning fuel. The battery provides what is demanded with silence in between.

Many generators have an Eco Mode that runs very slowly when there is no load, but automatically kicks up the power when needed.

[markopolo]

Originally Posted by DUTCH in Atlanta

A 2000 watt generator will not run a Dometic Rooftop A/C which draws about 3400 watts.

Running a rooftop A/C using a small generator can be problematic but there are maybe thousand of success stories out there about running 13.5k BTU rooftop a/c using Honda 2000's and others.

Initial startup surge and altitude are probably the two biggest causes of problems.

For those where startup is problematic a hard start capacitor would often solve the problem. For those where startup and running was problematic a soft start device like a Micro-Air EasyStart would usually solve the problem.

The older Honda EU2000i is only rated for 1600W continuous operation. The new Honda EU2200i is rated for 1800W continuous operation in the same size package.

Originally Posted by Winetime1

One other consideration is the generator has a limited run time and I hear they sometimes don’t perform well under load. As your a/c cycles on and off, the generator continues to run, burning fuel. The battery provides what is demanded with silence in between.

Batteries can provide limited A/C run-time - measured in hours at best and then some sort of generated power is needed to recharge the batteries. A/C run-time on a generator can easily be measured in days or weeks as long as you have a fuel supply.

Fuel burn rate varies with the load even with a constant RPM generator like an Onan. Fuel consumption for the gas engine Onan 2800W used in gas engine B vans is listed in the manual as being:

No load 0.16 gph
Half load 0.28 gph
Full load 0.46 gph

[Jostalli]

Originally Posted by avanti

I am open to all suggestions. My three primary goals are (1) quiet; (2) quiet; and (3) quiet. All else being equal, I would prefer DC for efficiency considerations, but it is clear the the advantages are small.

I have been seriously considering a split unit with underbody mount. I know ProAir's line in this area very well. However, doing this reliably would be a lot of work. The ARV 120VAC rooftop unit has received such good reviews, I am now considering that. It would certainly be easier. But the new ProAIr DC unit seems to be on the rise. I am looking for actual data that compares these two alternatives. As I said, I am also always open to new suggestions.

Quiet is not our goal but the DC A/C’s are all much quieter than the commonly used RV A/C’s. If quiet is a priority then definitely go with a split.

We focus on max efficiency and run time off-grid. For rooftop we like Kingtec. For split units we like Cruise N Comfort. The reason we haven’t installed a ProAir is because they don’t make a smaller unit. Their 20,000 btu model simply draws too much. In vans with limited load carrying capacity we don’t want to install more than 800-900 Ah lithium batteries. Both the Kingtec and Cruise N Comfort provide nice cooling at under 50 amps.

[jharrell]

Originally Posted by markopolo

For those where startup is problematic a hard start capacitor would often solve the problem. For those where startup and running was problematic a soft start device like a Micro-Air EasyStart would usually solve the problem.

The older Honda EU2000i is only rated for 1600W continuous operation. The new Honda EU2200i is rated for 1800W continuous operation in the same size package.

I have a Micro-Air Easystart on My 15k Coleman in my 30 amp Class A. I can confirm its works very well. I put it on due to running my whole coach off my Magnum 3000 and the 70A startup surge was causing the Magnum to occasionally complain even when on shore power due to voltage sag.

With the Easy-Start I can easily start and run the A/C off my inverter, it cut the startup surge way down. I have no real use for running the A/C off battery as I only have two Lifeline GC-4 AGM's and they will only run the A/C 30-45 minutes until 50% SOC. I can however greatly extend that by idling my V10 with stock 175 amp alternator, I normally just run the gas generator however.

Originally Posted by markopolo

Batteries can provide limited A/C run-time - measured in hours at best and then some sort of generated power is needed to recharge the batteries. A/C run-time on a generator can easily be measured in days or weeks as long as you have a fuel supply.

A Honda 2000/2200 will run about 4 hours on a gallon running a A/C, its very efficient being a inverter based design. This is also the reason it varies RPM since its frequency output is not tied to the engine speed as it is with a normal generator.

A 10kwh lithium pack can run an A/C for 8 hours, you then need to charge it back up. If you use a 8kw alternator off the Mercedes Diesel assuming .5 GPH you end up at nearly the same consumption, perhaps a little more, but its coming off the vehicle tank rather than carrying separate fuel.

Originally Posted by markopolo

Fuel burn rate varies with the load even with a constant RPM generator like an Onan. Fuel consumption for the gas engine Onan 2800W used in gas engine B vans is listed in the manual as being:

No load 0.16 gph
Half load 0.28 gph
Full load 0.46 gph

As a comparison the same generator using LP that the OP is promoting is only 2500W and its consumption is:

No load 0.3 gph
Half load 0.4 gph
Full load 0.6 gph

Propane is less energy dense than gasoline and gasoline is less energy dense than diesel.

I do wish Onan would do smaller inverter based designs, their QD 6000 and 8000 are inverter diesel and very efficient.

[Bud]

I understand that maybe all? the battery powered ac has been 110 volt ac from an inverter. The ac needs more amps or easy start to start up, no problem with an inverter.

How does this work with a dc powered ac and just batteries. The start up simply needs fewer amps? Fire up the compressor slowly.

[jharrell]

Originally Posted by Bud

I understand that maybe all? the battery powered ac has been 110 volt ac from an inverter. The ac needs more amps or easy start to start up, no problem with an inverter.

How does this work with a dc powered ac and just batteries. The start up simply needs fewer amps? Fire up the compressor slowly.

If its a brushless DC motor then the motor controller is essentially a inverter controlled by a computer which can do its own soft start sequence directly.

If its a brushed DC its still going to a have a large startup surge but only needs to be handled by batteries and cables with no inverter trying to deal with the surge too. Think engine starting motor cranking amps.

DC will be more efficient since as there are no inverter losses, even in the case of brushless where its actually an inverter for motor control its high frequency and inverting exactly at the frequency for the motor speed making actually the most efficient.

[Dogman]

Hello, I created a Group for anyone wanting to JOIN here in Class B Forum. Just CLICK, the link to join and ENJOY!!!

http://www.classbforum.com/forums/gr...batteries.html

[IdleUp]

In my article: http://www.rotory.com/sprinter/lithium/ I touched briefly on ProAir's new 12 volt brush-less motor roof top AC unit. I feel this is eventually where its going for lithium powered coaches since it runs directly off the battery no inverter loss.
Presently the only drawback is these units are a bit on the large size 20,000 btu for smaller B /B+ van use. Of course they also make larger in cabin mount units up to 60,000 btu.

Mike

[Dogman]

Hello, yet again, as I wanted to let anyone interested in knowing I created a social Group in this forum called "COACHMEN Galleria"

Here is the link and above you can click on COMMUNITY then SOCIAL GROUPS or just click this link.
https://www.classbforum.com/forums/g...+galleria.html

[DUTCH in Atlanta]

For what it's worth, the Coachmen Galleria is NOT and never has been built on a T1N Sprinter chassis. It was built on the NCV3 Sprinter chassis and currently is built on the VS30 Sprinter chassis.

It would be good to post accurate information in your group.

Also, as much as I dislike Facebook, there is an excellent Facebook Group for the Galleria located here:

https://www.facebook.com/groups/1694449227542056/

Lots of Galleria owners sharing good, pertinent, valuable and accurate information posting there about this coach.