Lithium ion battery pack ?

[Cooterbrown]

Does it make sense to order the solar panel package when ordering the lithium ion battery pack ? Will the 640 amp hours be sufficient or will you need to purchase extra battery pack from the dealer ?

[Danny969]

For a class B or small/mid size class C, 640 ah is normally enough. Yes you should get solar as you probably have a 12V fridge and the solar will offset most of the daily use. I assume you'll also have a second alternator to charge that battery pack.

[Isaac-1]

There are too many variables to give any meaningful answer to this question, like how do you use your RV, where and when do you use it, do you have a residential or absorption refrigerator, ...


A 640AH battery might provide enough power for a minimalist with an absorption refrigerator for a week, or 1 day for an all electric coach with residential refrigerator, ....

[vsheetz]

Originally Posted by Cooterbrown

Does it make sense to order the solar panel package when ordering the lithium ion battery pack ? Will the 640 amp hours be sufficient or will you need to purchase extra battery pack from the dealer ?

Not knowing anything more than your question, its impossible to answer specifically.

Solar is just another battery charger - it can reduce or eliminate generator or other charging source time.

Whether 640ah battery is sufficient depends on your usage and goals. At a minimum you want enough capacity to last through the night.

###
My experience as example.

We've 600ah lithium and 1500w solar flat mounted on a 40' DP motorhome with residential refrigerator.

Our typical cycle...
Is to let the solar charge during the day as it can. Then when preparing dinner or at end of sun, the generator is run as needed to get fully charged (time needed varies from a couple hours in low winter sun to none in mid summer - or several hours if bad solar production day). The batteries then easily last through till the next morning.
The cycle begins again...

[Cooterbrown]

Thanks All - should have provided more info - we are ordering a 2023 Mountain Aire and considering the lithium batteries with the solar panel package- we will be part time, summer vacation weekends etc - may do some boondocking from time to time. Just wanted some basic feedback from folks who have lithium and solar to see how effective it is and how it’s working- I’m also curious what the additional battery pack will cost ?

[Isaac-1]

I suspect you will be looking at a $5,000+ upgrade charge, maybe more as prices on the same batteries I used are up more than 20% on list price, and I bought mine at a special discount. I installed 420AH of 12V commercial LiFePo4 batteries last year for roughly $2,000 by shopping for deals and as a DIY project, I already had 400 watts of solar which was installed on my coach by the previous owner in 2015.


I consider 400 watt of solar with a absorption style refrigerator just about the minimum to be off grid sustainable, 600-800 watts would be much better, but not enough better for it to be worth it to me to rip out what I have and upgrade. The big thing my current setup gives me is the ability to be flexible and minimize generator run time. Even without the solar the LiFePo4 batteries can accept a charge much faster than the old lead acid batteries.


With lead acid batteries that are mostly / fully drained no matter how big of charger it takes about 4 hours to charge to the 80% mark, and another 4 hours to get to 100%, that means 8 hours of charging from whatever source it might be generator or solar to fully top off a lead acid battery bank. By contrast LiFePo4 batteries can accept charge at the 1C rate from almost empty to almost full (it slows some in the top 5%, mostly in the top 1%). Meaning with a big enough charger (and big enough generator), you could in theory fully charge the LiFePo4 batteries in 1 hour, though to maximize life it is best to limit them to 2C, or 2 hours to fully charge.


What this means for me is that I have 420AH of LiFePo4 batteries, up to 30 amps of solar input (in perfect conditions), 60 amps of input from my primary RV converter, and another 50 amp dedicated Lithium charger which allows me to pump power into the LiFePo4 bank at a rate of about 110 amps per hour, not counting solar input while running the generator which could fully charge the battery bank in under 4 hours from generator power. I have thought about increasing the size of my converter to allow for faster charging, just have not done it yet. Note this is about a 2,000 watt drain on the generator, and I have a 4000 watt onan, so charging plus running the air conditioner just about maxes out the generator. In the real world I would likely never run the generator 4 hours straight to top off the batteries, instead I would run it as needed, such as while cooking and using the microwave/convection oven or air fryer, and let the surplus go to topping off the batteries if the solar was not doing the job. If the solar was doing the job then I could run the microwave or air fryer off my 2000 watt inverter, but I would only tend to do that if I knew I was in a place where the solar could keep up (cooking french fries in the air fryer for 15 minutes would take the solar panels about an hour or so to replenish.

[pasdad1]

Ordering a 2023 MADP, I’m guessing your questions are more about utility than cost, since the up charge is still a drop in the bucket compared to the cost of the coach.

I would say it it is never a bad thing to have lithium and solar, it gives you more flexibility and more capacity.

Where do you store the RV? At your house? In storage with power? Or at storage with no power available?

Lithium batteries with solar will pretty much eliminate the need to keep the RV plugged into power.

At the very least you want AGM batteries if you don’t go with lithium, that way worrying about keeping water in the batteries is eliminated.

What brand of batteries does the factory offer?

[Cooterbrown]

Will be stored indoors at our house and plugged into 50amp electrical - not sure who Newmar is using as a battery vendor ? Just know it’s 640ah pack and you can have the dealer add an additional 320ah pack if necessary it comes pre Plumbed from the factory.

[vsheetz]

The most talked about advantages of lithium batteries are capacity and longevity.

Less talked about, and not appreciated until having lithium batteries is the improved user experience when dry camping.

The bit higher voltage and very flat discharge curve keep the battery at 13+ volts most all the time. Plus they sag very little under heavy load. So the performance is consistent throughout the typical discharge cycle. Appliances and such in the coach just work better.

Lithium charge faster. Better usage of solar production, less generator run time, etc.

The BMS (battery management system) prevents damage to the battery. Overly discharging or charging, temperature excursions, etc. The BMS shuts down to protect the battery.

[Isaac-1]

Another big advantage of Lithium batteries is they don't care if they are fully charged or not, as long as you don't let them fully discharge they will be happy, in fact they will last longer if stored at a lower charge level, such as 50%.

[Danny969]

It looks like they charge 5K for 400w of solar. They're probably using the Lithonics 640ah battery and probably charge $20K for that. The additional 320ah battery is probably another $10K. I would get all of these simply because at the price of that coach, this is a drop in the bucket and lithium far out performs AGM. Even with a full size fridge you should last a few days (not including air conditioning) if you don't go go hog wild with your energy use.

[pasdad1]

Originally Posted by Cooterbrown

Will be stored indoors at our house and plugged into 50amp electrical - not sure who Newmar is using as a battery vendor ? Just know it’s 640ah pack and you can have the dealer add an additional 320ah pack if necessary it comes pre Plumbed from the factory.

With just summer vacations and weekend usage, doubtful you will actually need lithium and solar, additionally storing indoors with 50amp power means you don’t need the solar to keep batteries charged while in storage.

Your diesel generator needs regular usage to keep it healthy, so unless you are boondocking for many weeks or months, don’t think you are doing your generator a service by NOT running it. Go ahead and run that generator for the occasional times you are not plugged into shore power.

How long do you anticipate keeping this new RV? Do you anticipate keeping it until you retire, and then traveling extensively?

If just keeping the rig a couple of years before trading or selling, the option will not appreciably add to the used value…..however if you intend to keep this RV a long time, you will realize more of the benefits of this newer technology.

It reminds me of the argument for the very early adoption of LED lighting. Today of course, it’s ubiquitous, and very desirable to have LED lighting in every RV and home. 10 years ago, it was available, but not easily obtainable or cheap. It made sense for the early adopters to spend the additional money back then if they used the RV for lots of boondocking, or intended to keep the RV a very long time.

[creativepart]

The short answer is YES, do it.

Will it be enough? When is there ever enough? It will be an asset that you’ll be glad you opted for on a top of the line production coach. It will never be an option you are sorry you have. It will make your coach more usable in more locations and if your needs change the flexibility will be nothing but a plus.

[Kid Gloves]

$25K-35K, may be a drop in the bucket compared to the price of a new coach. It is also wildly overpriced for the proposed upgrade. If those prices are accurate, I’d give the factory option a big No. There’s really no point in enriching Newmar any more than necessary.

To the original questions, we’d need to know your energy needs and usage patterns to determine an appropriately sized battery, where you’ll be parking, sun or shade, in order to determine the size of a solar array that will be capable of charging the battery. If you need all or most of a 600-900Ah battery, it won’t get fully charged from 400 watts of solar panels in one day.

We’re retired, but don’t use the coach extensively. Sometimes we go out for a month or two, sometimes it sits for a month or two. We might go out for a week, or 3 days or 10 days, then it might sit for a week or three months? We have lithium batteries and solar panels that suit our needs. I don’t believe there is a prescribed usage pattern that must be met in order to trigger the decision to choose lithium and solar.

We store indoors with a 50A outlet. Since we converted to lithium, I no longer plug the coach in. I just put a maintainer on the chassis batteries and let the lithium batteries sit. There’s no need to charge them or keep them topped off. They don’t need water, there’s no corrosion on the terminals and after 2 months they are nowhere near discharged.

I would encourage you to add lithium batteries and solar panels from a source other than the dealer.