Battery vs. generator

[rudy558]

Hi all,

I’m new here and wasn’t sure whether to post this in “new to RVing Purchase Questions and concerns”, “full timing in your grand design RV”, “general tech”, “appliances”, etc. sorry in advance if someone has to move it!

Background: We’re about to buy a brand new 2023 337RLS and plan to live in it full time. We’re parking it on family property and plan to put it under a carport to decrease exposure to the elements. I know this will eliminate the usefulness of the solar, but I feel it’s worth it to prevent leaks and roof issues (opinions welcome). It has a 16 cu. ft. 12vt fridge and 2 a/cs. Can provide more info if needed.
The power where we’re parking goes out at least a few times per year.

Q: what should I buy to keep the RV powered during power outages? My main concerns are keeping the fridge running and the temperature of the RV controlled. Everything else we can use battery banks or go inside for.

Thank you in advance!

 

[Hoopy Frood]

IMO, it boils down to what you consider is necessary to keep "the temperature of the RV controlled". How hot does it get, and conversely, how cold does it get. If you need A/C frequently and for a lengthy period of time, the battery powered approach won't do the trick.

 

[kb0zke]

Is this going to be a (mostly) permanently parked trailer? If so, you might want to consider making sure that the roof of the cover can handle the weight of a bunch of solar panels. You will want that cover tall enough to drive under anyway, so that ought to give you enough airflow around the a/c units. A small shed on the side can handle the batteries, Victron Multiplus II, etc. as well as your 50A connection. A small lean-to on the side of that shed (really, just a roof and whatever screen material you want/need) will take care of a generator with an auto-start on it. Let the sun provide a large portion of your energy needs, with other connections complementing it.

The advantage of this is that the trailer is still quite usable as a mobile apartment when you want to travel. All you need do is your normal disconnecting of whatever utilities you have connected. The solar panel on the roof would still be there to power the refrigerator as you are traveling, just as Grand Design planned.

 

[Second Chance]

Thinking more traditionally... if you're going to be permanently located, consider a larger standby generator with a larger fuel tank. You could rig it up with auto-sensing start and and automatic transfer switch to switch from shore power to the generator when the power goes out. This is how homes with standby generators are set up. Being stationary, you could choose a generator that is big enough to handle all your needs (ACs included) and put it on a paver pad with a cover for protection. With a generator, you won't have to worry about shading solar panels, rainy/cloudy days, a large, expensive battery bank, etc.

Rob

 

[Riverbug]

That's a pretty open-ended question. As others stated - it depends on what you need to power and for how long. Most would probably start with a generator. Go small to cover the basics unless A/C is required. A good start is also to swap the crappy battery that likely came with the RV for a lithium (say 206AH SOK as an example). Without doing anything else, that would give you much more battery capacity even if you don't have a lithium capable charger to start with. Then, give it time. See how much you really need backup power and how you really use the RV. Then you can decide if you want to add solar, lithium, inverter, or larger generator, if you want a serious battery bank you can research DIY lithium batteries but that takes time to research. Good luck!

 

[JPS350]

What Rob said. If you go with a generator and plug the trailer in the rest of the time, there's no reason to upgrade your battery. Choosing a generator, you just need to know whether you want to run the ac or just everything else minus the ac. That will determine how big of a generator you want to look at.

 

[rudy558]

IMO, it boils down to what you consider is necessary to keep "the temperature of the RV controlled". How hot does it get, and conversely, how cold does it get. If you need A/C frequently and for a lengthy period of time, the battery powered approach won't do the trick.

Good point about conditions where I live! I'm in the pacific northwest, so our winters range from mild to fairly cold. The most severe weather is a northeastern wind that hits pretty hard at 60+ miles per hour and get as cold as 12 degrees. The RV will be behind a pole barn and shipping container used for storage. This should help protect it from the wind. We also get snow. This is part of what causes the power outages.
Our summers have gotten more severe lately. Occasionally we have days in the 90s and very rarely in the 100s.

I essentially want enough power to keep the fridge/freezer running along with the a/c. I'm new to RVing, so I could be wrong, but the heat is usually gas, right? So, I'm not as worried about that.

 

[rudy558]

Is this going to be a (mostly) permanently parked trailer? If so, you might want to consider making sure that the roof of the cover can handle the weight of a bunch of solar panels. You will want that cover tall enough to drive under anyway, so that ought to give you enough airflow around the a/c units. A small shed on the side can handle the batteries, Victron Multiplus II, etc. as well as your 50A connection. A small lean-to on the side of that shed (really, just a roof and whatever screen material you want/need) will take care of a generator with an auto-start on it. Let the sun provide a large portion of your energy needs, with other connections complementing it.

The advantage of this is that the trailer is still quite usable as a mobile apartment when you want to travel. All you need do is your normal disconnecting of whatever utilities you have connected. The solar panel on the roof would still be there to power the refrigerator as you are traveling, just as Grand Design planned.

Yes, it will be permanently parked. Excellent point about the room for the a/c to have airflow! I'd somewhat forgotten about that. It'll take us a while to build a proper shelter for it, so we were planning to start with a few car tents from amazon or something. Now I'm wondering if they'll have enough space above them for the a/c. Any idea how much room they need?

Once we have the more permanent shelter we could consider putting the panels on top of that. Can the panels that come with GD be moved like that or would I need to buy a separate set?

Love the idea of a lean to for a generator or batteries!

 

[rudy558]

Response to Second Chance:

Love this idea! Any tips for picking a generator? I'm absolutely new to this stuff and am not sure where to start.

 

[rudy558]

Response to Riverbug:

Good to know that the battery that comes with it could probably use replacing. What do you mean by a lithium capable charger? Would the connections on the RV for the original battery not work?

Any suggestions for how to figure out how much backup power I need?

 

[rudy558]

What Rob said. If you go with a generator and plug the trailer in the rest of the time, there's no reason to upgrade your battery. Choosing a generator, you just need to know whether you want to run the ac or just everything else minus the ac. That will determine how big of a generator you want to look at.

Ok, so maybe if I get a generator I don't need to replace the battery? I'm curious about the pros and cons of both. Why someone would want one vs the other.

 

[Riverbug]

Generators are going to be cheaper than solar/lithium setups that would accomplish the same task, and easier to install. Understanding better now what you are going for, a generator would be a more cost effective and easier. You will need an auto-start feature if you want it to run while you are away. Unless you are attempting to get off-grid at your location, you can save yourself lots of time and money by going the generator route. Solar/lithium is great for people wanting to get off-grid at home or on the road.

Related to your previous question about what I meant by lithium capable charger...lithium has a different charge profile than lead acid. A typical lead acid charger cannot charge to the voltage required to get a lithium battery to 100%. But if your RV doesn't already have a lithium setting on the charger you could still use if on your lithium battery, it just will never get to 100%. But a lithium battery charged to 80% will still have more capacity than a typical lead acid because you can use 100% of the battery without degradation. With lead acid, every time it is depleted below about 50% it is being degraded. That is why many people end up replacing them every 2 or 3 years - they come to the RV to find the battery is completely dead and if this is repeated too many times, they end up having to replace it. If the lead acid is kept charged up and not depleted below 50%, I typically get 6+ years out of my AGM's on our boat.

 

[JPS350]

Ok, so maybe if I get a generator I don't need to replace the battery? I'm curious about the pros and cons of both. Why someone would want one vs the other.

This can get involved,but it all comes down to the amount of storage you need for what you want to do. If you're always going to be plugged in or on generator power, you need very little, so what you have will be fine. If you were going to be camping off grid and wanted to minimize or eliminate generator use, the situation would be much different.

Don't get me wrong, I love solar power in the right circumstances. One data point for you. We have an off grid 400 sq ft. log cabin (on wheels, so it's certified as a park model home), that we spend spring and fall in. It's powered with a 1 kw solar system, large battery bank storage, and 3kw inverter. Works great for us but we heat it with a wood stove, and just run a small window ac in the bedroom when needed, and we run a residential fridge. We still use a generator backup to charge the battery bank if we get many cloudy days in a row or when I run the ac much. I also have a solar system on our sailboat, and solar is great for that.

In your case, you'll be plugged into power all the time, and only need power for emergencies. This is a perfect use for a generator, and would be the most cost effective one. You could put a very expensive solar system in with expensive battery storage and still need a generator at times. So, it makes more sense to go with a generator first, and if you want to dabble with solar once you know your power needs do that later as you gain experience.

Size generator and brand...you'll get tons of opinions. The size will depend on whether you have 1 15k btu ac units in that trailer or 2. If only 1, you would likely need at least a 3500 watt generator. You could install a soft start unit on the ac to make starting them easier and reduce surge current. This would be important if you were trying to run 2 of them off a 3500 watt generator. Brand is a heated question on these forums, but if it were me depending on one to start in 10 degree weather, it would be a Honda. I admit to being biased, but you can't go wrong with one. The only drawback is the price.

Maybe more important than any of the above are things you may or may not thought of. Did you get the 4 season insulation upgrade on the unit? Does it come with a 50 A or 30 A power plug? What are your options for the outlet where you are, and what is the length of the run and wire size to the main panel? You have to think about how much amperage is actually available where you want to plug it in, and whether you will have enough current to start the ac's and run them properly. If it's marginal, you might need to install soft starts even if you're plugged in. Another interesting soft start idea can be found if you look up Active Start. It's an inline soft start that goes between the power source and the rv. I can't vouch for it as I don't own one, but it's a neat idea that could help you run things off your plug in power source and a generator without wiring in dedicated soft starts.

 

[robmcqueen]

Maybe set up a home back-up generator ran on propane so you would never be without power to the trailer even if you were away the generator would start during a power outage.

 

[Sleeping Rainbows]

I think [MENTION=34944]robmcqueen[/MENTION] has the right idea.
Generac is a good choice.
Home Depot, Lowes and Walmart have competitive prices and will hook you up with professional installers.

 

[Second Chance]

I think #robmcqueen has the right idea.
Generac is a good choice.
Home Depot, Lowes and Walmart have competitive prices and will hook you up with professional installers.

[MENTION=22753]Sleeping Rainbows[/MENTION]

The "@" sign is used to tag members rather than the pound sign...

Rob

 

[Sleeping Rainbows]

[MENTION=22753]Sleeping Rainbows[/MENTION]

The "@" sign is used to tag members rather than the pound sign...

Rob

Thanks, Rob. Fat fingers.

 

[rudy558]

Thanks so much everyone! This has been immensely helpful. So, sounds like my best bet is a generator.

 

[JPS350]

Not sure where this flow chart came from other than I stole it from a boating generator discussion on a sailing Facebook group. Enjoy!