Boondocking Generator Questions

[bbrault]

Hi, I am looking at getting a new 2022 Legacy with the Lithium Pro package and Truma AC for mostly boondocking. 

Unfortunately a Honda 2000i won’t fit into the front basket so I was hoping that I might use my Yamaha 2000 EF 2000i. It’s a 1600W with 2000W peak. 

I understand that this generator will not be able to do everything at once like charging the lithium and running the AC. It might actually not be able to start the AC. But since the AC can run from the Lithium inverter ( for a very short period), I was hoping that the inverter could start the AC and the generator could later sustain it. 
Then when I am no longer running the AC, the generator could charge the Lithium. 

Your insights and/or advices on the above would be most welcomed. Don’t be afraid to go technical, I am an electrical engineer. 
 

Thank You for your input. 
 

[katanapilot]

Not sure why you think the Honda 2000i won't fit into the front basket - we carry two Honda 2200i generators there.

As to the ability to start the Truma A/C with one 2000i, I'm not sure.  What I did discover on our recent trip was that use of the "ECO" mode does not work well during the startup of our Houghton A/C.  I think the Truma may have a lower inrush current than the Houghton - which has a much lower startup current than the stock Dometic.

Our experience was with both Honda generators paralleled and both in ECO mode.  When I switched it off, the generators worked fine.

[bbrault]

Sorry, I was referring to the Honda 2200i that won’t fit. 

The specs size I got for the Elite I basket size is 26.75 x 14.375 x 7.75 (L x W x H) in.

I don’t see how you can fit the 2200 or 2 2000. 

You possibly have an Elite II?
 

[Dave and Kimberly]

So a question to those of you who might understand this stuff better than I:

    In our case, we have the Solar panels, with the Lithium batteries (390AH)... and the 3000 watt inverter.    I hear so many question how big of a generator would be necessary... and you will hear the discussion on surge watts and so on.   Since my set up allows me to run the A/C from the batteries... why couldn't I operate off of a much smaller generator (even say a Honda EU 1000)... and then back fill the batteries from the generator as needed. 

   I'm not sure I would do this... but it's just a thought and knowing it could work might be beneficial to some at least.   The point is that the "generator" doesn't need to power the A/C directly. (I think?)

[dewdev]

I have seen on this forum where people are using a inverter generator (like a 1000 watt) to charge just their batteries.

[SeaDawg]

A higher wattage generator will charge lithium batteries faster. And, they can accept fast charges.

We have agms. Solar does the heavy lifting, with our Honda 1000 as backup. We use the 1000 genset early in the day, bulk mode, to let the free solar do the slow charging, later and slower, as necessary. Much of the time, we don't need a genset.

I don't know about you, but I don't want to carry a genset I can't easily lift. And, I don't want a big genset on the tongue.  It's all about your comfort zone, how you camp, your tow vehicle, etc

 

[bbrault]

Dave and Kim

Several reasons
1- The AC will drain your Lithium in an hour or so. 
2- A 1000W generator would then take 4-5 hours to recharge your Lithium. 
3- Your expensive Lithium will only take a few hundred charge/discharge cycles. 
 

I cannot think of many good reasons to run the AC on Lithium except for short exceptions and mostly to help start the AC and then run it from a Generator if the Oly can do that. 
 

Thats what I am trying to find out. 

[bbrault]

SeaDawg

i totally agree with you. 
i also want to carry the smallest possible generator. 
 

 

[SeaDawg]

If you want to power the ac from a genset, you'll need more than a Honda 1000. With the dometic, with an easy start, at least a 2200, I'd think.

We rarely use ac. The Honda 1000 is strictly for charging the batteries,  along with solar.

[Steph and Dud B]

Here are our recent experiences with this. For reference, we have the larger lithium package (630 Ah) with the soft-start Dometic A/C and an older Honda EU2000i (2000W surge, 1600W continuous):

Dry camping.  Weather: low-80s, humid. Trailer solar panels in full sun. Thermostat set to 70 degrees. 

Started generator at 11:30 AM daily and ran the A/C off the generator until 1:30. This also provided a very small charge to the batteries, enough to replace what we had used overnight. (We limited Xantrex setting #28 to 15A.)

Shut the generator off at 1:30 and ran the A/C off the battery bank/solar until 4:30. This depleted it to 70-80% SOC.

Shut A/C off at 4:30 and restarted generator. Used microwave, etc. for dinner and batteries were fully charged by 6:30.

Our reason to use the A/C on batteries was to spare our neighbors the generator noise during midday. (Most people around us were running their generators around lunch and dinner, too.)

So, in those conditions we were able to run A/C on batteries for 3 hours and replenish that in 2 hours with the generator. We used approx. 1 gallon of gas daily in this mode. (Because lithiums take a charge so well, the little generator ran full out while recharging).

Our little 2000W Honda did fine running the A/C or charging the batteries, so the original poster's Yamaha should do just as well. However, if we wanted to bulk charge our batteries and run the A/C simultaneously we'd probably need a bigger generator.

Hope this helps. 

 

[bbrault]

Hi Steph and Dud

This is very useful. 
Is it possible to start the AC using the inverter and then switch from the inverter to the generator without the AC dropping off?

 

The new AC may need a large inrush that inverter can handle but possibly not my 1600/2000 watts generator. 
 

Thank You for your comments. 

[ScubaRx]

On 8/31/2022 at 12:46 PM, bbrault said:

Is it possible to start the AC using the inverter and then switch from the inverter to the generator without the AC dropping off?

The compressor kicks on and off while running to maintain a reasonably constant temperature. I would expect that every time the AC compressor kicked back on it would overpower the generator, unless the inverter was left on all the time and could take up the slack the generator was unable to provide? Don't know if that is possible or if it would work.

[ScubaRx]

On 8/30/2022 at 6:31 PM, bbrault said:

1- The AC will drain your Lithium in an hour or so. 

2- A 1000W generator would then take 4-5 hours to recharge your Lithium. 
3- Your expensive Lithium will only take a few hundred charge/discharge cycles.

Let me expand on this a bit.

1- The AC will drain your Lithium batteries if used for too long, but it won't do it in an hour.

2- A 1000W generator can output a maximum of just over 8 Amps. If you've used 360 amps out of your batteries running the AC for several hours it will take this generator nearly two days to recharge your batteries.

3- LiFePo batteries can take thousands of cycles.

[Steve and MA]

Assuming no power losses when using an inverter or charger, wouldn't a 1000 watt generator producing 8 amps at 120 volts be able to charge a 12 volt battery at 80 amps?  

[bbrault]

I actually have a 1600W/2000W peak generator. I am considering the Legacy I with Lithium Pro and Truma AC. 
It probably has 200AH useable. It should take more than a few hours to recharge the batteries. 
My real concern is powering the Truma from the generator. I cannot fit a bigger generator in the front basket so a 2200W is not an option. 
Someone made a very good point about the compressor kicking on and off. 
 

[rideandfly]

Our Honda EU2000i gen-set that's 1600W continuous and 2000W peak runs our Dometic 13.5K AC fine with the Microair EZ start installed.  Only run one major appliance at a time with the gen-set, AC or Microwave or hot water heater. When charging the Battleborn lithium battery when it's between 70% & 80%, let the single 100AH battery charge close to 100% for around 60 minutes before running a major appliance. Right now we only have one 100W Renogy solar suitcase panel, but will probably increase to two 100W solar suitcases and we don't have factory solar or inverter. It takes a while for the single 100W panel to take the battery to 100% depending on solar charge conditions, that's why I want to increase to two solar panels.

[ScubaRx]

On 9/3/2022 at 1:57 AM, Steve and MA said:

Assuming no power losses when using an inverter or charger, wouldn't a 1000 watt generator producing 8 amps at 120 volts be able to charge a 12 volt battery at 80 amps?  

Not exactly. The numbers you used to arrive at this conclusion are accurate: 10x the voltage, 10x the amperage.

But, the voltage output from the generator is supplied to and used by the trailer's onboard battery charger. The amp output of the charger determines how many amps are going into the battery.

[Rivernerd]

On 9/3/2022 at 6:22 AM, bbrault said:

My real concern is powering the Truma from the generator. I cannot fit a bigger generator in the front basket so a 2200W is not an option. 

To my knowledge, Oliver has not yet installed any Truma Aventa Eco air conditioners in any trailers sold to customers.  So, there is no "real world" experience to draw from.  But, posters on this Forum have advised that Oliver has installed a Truma Aventa Eco in a demo trailer being shown to customers at the factory, and that Oliver has done some testing of that air conditioner before deciding to offer it in production models.

As I read the specs, the Truma Aventa Eco draws 10.8A on "high," fewer than 10A at lower speeds.  As it operates on 120V power, it will pull 1296 watts on "high" (voltsxamps=watts).  This math suggests that your 1600/2000 watt generator should be able to keep up with 1296 watts of non-startup power demand.

What I cannot find is how many watts the Truma Aventa Aco draws at compressor startup.  It is touted as "30% more efficient than traditional 13.5k BTU rooftop units."  Does this mean it is also more efficient at startup?  I don't know.  But, Oliver commonly installs Micro-Air Easy Start modules in AC units to help generators deal with compressor startup power demand. 

So, I recommend you ask your Oliver salesperson:

1.  If Oliver's tests have indicated what the Truma Aventa Eco startup power demand is;

2.  Whether Oliver has tested the Truma Aventa Eco with and without the Micro Air Easy Start;

3.  Whether Oliver has tested the Truma Aventa Eco on generator power, and if so, the rated output of that generator; and

4.  Whether Oliver is planning to install Micro Air Easy Start modules in the Truma Aventa Eco units that will be installed in 2023 model Oliver trailers.

The answers to those questions should inform your judgment as to whether your Yamaha 2000/1600 watt generator will be adequate to both start and run the Truma Aventa Eco, and whether installation of a Micro Air Easy Start module would be required.

Please post what you learn from your Oliver salesperson on this thread.  I expect you are not the only person interested in the results.

[bbrault]

Rivernerd

This is very helpful information. 
I will work with my salesperson in getting these answers and I will post back my findings as you suggested. 
 

Thank You very much for your comments. 

[Steve Morris]

2 hours ago, Rivernerd said:

2.  Whether Oliver has tested the Truma Aventa Eco with and without the Micro Air Easy Start

Anita told us they a soft start option is not needed with the Truma, nor would one be offered as an option with the Truma package. 

[John E Davies]

On 8/30/2022 at 4:31 PM, bbrault said:

3- Your expensive Lithium will only take a few hundred charge/discharge cycles. 

This is incorrect for all brands of lithium RV batteries.

I don’t camp a lot of days, but toward the end of my second season with 200 AH of Battle Borns, they have only had 15 actual cycles…. because I rarely run the State of Charge very far down. Usually the panels catch up each day after a minimal discharge overnight. For a residence that has daily deep cycles from its solar installation, the cycles can add up very fast indeed.

Going by the above chart an Ollie owner could expect six YEARS of once a day deep discharges before it deteriorates to 80% of its original capacity. I expect my BB batteries to essentially outlive me 😬 This is just one reason switching to Lithiums makes so much sense for owners when their lead acid batteries die,  especially if they expect to own the trailer for more than three or four years.

John Davies

Spokane WA

[Rivernerd]

48 minutes ago, Steve and Deb said:

Anita told us they a soft start option is not needed with the Truma, nor would one be offered as an option with the Truma package. 

Did Anita happen to tell you how much generator power is needed to start up the Truma Aventa Eco, without the Micro Air Easy Start?

[ScubaRx]

Sales told me that the folks at Truma had said that if the MICROAIR Easy Start system was installed in one of their AC units that the warranty would not be honored. This is the reason that it is not offered as an option.

I copied this from this Site:

Will My Generator Run a Truma Aventa RV Air Conditioner?

You’d need a 3,000 Watt generator (or a 3,000 Watt inverter) to operate either model of the Truma Aventa. This is due to the power surge required at start-up.

We have no information as to whether the Truma Aventa is compatible with something like our Microair EasyStart 364 to handle the initial surge, but that would be a good question for Truma!

 

[Rivernerd]

13 minutes ago, ScubaRx said:

Sales told me that the folks at Truma had said that if the MICROAIR Easy Start system was installed in one of their AC units that the warranty would not be honored. This is the reason that it is not offered as an option.

Good to know. 

Since Oliver can't install a Micro Air Easy Start in a Truma Aventa Eco air conditioner, does anyone know how much generator wattage is required to start it up?

[ScubaRx]

26 minutes ago, Rivernerd said:

Good to know. 

Since Oliver can't install a Micro Air Easy Start in a Truma Aventa Eco air conditioner, does anyone know how much generator wattage is required to start it up?

I've really searched for that information. Even though I don't have a dog in this race, I tried. Apparently the locked rotor amp (start-up amps) are not published. The running amps are as follows.

• Low speed = 9.4 amps AC (or 104 amps DC)
• Medium speed = 9.6 amps AC (106 amps DC)
• High speed = 10.5 amps AC (116 amps DC)