Guidance on Lithium Ion & Solar

[AirNubie]

Hello all,

Wondering if this might be a first step toward a solid Solar + Lithium Battery setup?

Expion360 EV-V120-2A-KIT Viper Power Cell Dual RV Kit (Airstream)... my understanding is that these lithium batteries were designed specifically for Airstreams and that they can drop in replace existing batteries.

If I started with these and 2 100W solar flex panels, can I later expand the system to add more solar and more battery capacity? Am hoping so... don't know for sure that I need a more robust and costly system. Typically just need 2-3 days of power and want to avoid having to run my generator.

Any tips or advice appreciated!

[SilverHouseDreams]

Originally Posted by AirNubie

Hello all,

Wondering if this might be a first step toward a solid Solar + Lithium Battery setup?

Expion360 EV-V120-2A-KIT Viper Power Cell Dual RV Kit (Airstream)... my understanding is that these lithium batteries were designed specifically for Airstreams and that they can drop in replace existing batteries.

If I started with these and 2 100W solar flex panels, can I later expand the system to add more solar and more battery capacity? Am hoping so... don't know for sure that I need a more robust and costly system. Typically just need 2-3 days of power and want to avoid having to run my generator.

Any tips or advice appreciated!

Clearly they are made "for an Airstream", because they cost 2X alternative options :P

So this kit is 240Ah of LFP battery and a Progressive Dynamics converter. The PD9160AL can be had for $217. 2 100Ah BattleBorns can be had for $1898. Total cost $2115, vs $4399 for this kit. Sure, they are including some battery bus bars to put them into parallel, and some new cables...but you can buy a lot of battery cable (and a solar charge controller, and some solar panels) with the $2284 in savings. They don't detail much about the cable lengths that they include, so how would one even know if they are adequate for any given trailer?

[switz]

We have five AM Solar 100 watt panels the roof of our 2015 23D and nine of them on the roof of our 2014 Classic (could put one more panel on the Classic's roof but would overload the charge controller). So five on a 25 should be easy.

[uncle_bob]

Originally Posted by gklott

Bob, where did anyone say "mandatory requirement for all RV's made" or "required by rules / law". I never did.

You appear to not understand the purpose of standards. No standard is mandatory until required by a Authority Having Jurisdiction (AHJ). Beyond federal codes related to trailers and recreational vehicles, there are few, if any, laws governing safety and health requirements for our trailers.

RV manufacturers voluntarily agree to follow NFPA 1192 when building our trailers.

Is there a stock RV with a two pole switch as I recommended? Probably not today. Why? The RV Industry Association does not yet recognize photovoltaics as a power source for any RV. See the brand new 2018 ANSI/RVIA low voltage standard, section 2.1 and the six power sources for an RV. The 2018 ANSI/RVIA LV standard does not contain the words 'solar' or 'photovoltaic'. Imagine that!

Where is someone to research the best safety and electrical practices for RV solar installation? The answer is NFPA 70, article 690. That's why I recommended it for anyone considering installing a photovoltaic power source for their Airstream.

NFPA estimates that there are over 20,000 RV fires each year [1]. By following the best practices industry has accumulated, we can reduce the chance that any AS owner adding solar power will experience a fire or injury from the photovoltaic system.

"not to say in any way that it's a bad idea" - Glad to know that you agree that following NEC 690 is not a bad idea. Thanks.

73/gus
[1] https://www.nps.gov/articles/p52-rv-fire-safety-101.htm

Hi

You toss up a batch of suggestions, ideas, thoughts, and present them all as if they are "the rules". That simply is not true and you are miss-representing the situation to anybody who does not do a lot of research.

The most basic way to demonstrate that is the complete lack of any RV set up the way you suggest. You can go on all you want about "legal this and sue that". The manufacturers simply do *not* set up RV's the way you think they should be done.

I (obviously) don't like FUD campaigns at all. That is very much what is going on here.

Bob

[AirNubie]

Silverhousedreams,

Spoke to the sales rep and it sounds like their main differentiation is
- each has an internal CPU controller is modular in each battery and that these can be replaced
- they are smaller and fit directly in the existing tongue box of the Airstream TT (group 24's vs. group 27's).... so take up less space
- they come with a rapid lithium charger
- comes w/ install kit

Agree this sounds pricy if I'm able to follow what you suggest and save 40% or so... anything here that you are seeing that might rationalize the price? If I go w/ your suggested setup, how do you suggest I accommodate the larger batteries? Where would you recommend I buy the components?

Thanks in advance!

[SilverHouseDreams]

Originally Posted by AirNubie

Silverhousedreams,

Spoke to the sales rep and it sounds like their main differentiation is
- each has an internal CPU controller is modular in each battery and that these can be replaced
- they are smaller and fit directly in the existing tongue box of the Airstream TT (group 24's vs. group 27's).... so take up less space
- they come with a rapid lithium charger
- comes w/ install kit

Agree this sounds pricy if I'm able to follow what you suggest and save 40% or so... anything here that you are seeing that might rationalize the price? If I go w/ your suggested setup, how do you suggest I accommodate the larger batteries? Where would you recommend I buy the components?

Thanks in advance!

One key question is the temperature range you desire to camp within. Most of us moved the lithium batteries “inside” and this solves the temperature issues with lithium, as you cannot charge them if they are outside with freezing temperatures.

My AS is different than yours, so I can’t necessarily say what will and won’t fit yours. But the BattleBorn battery dimensions are on their site and you can compare them to your battery box to determine feasibility. You could likely modify the battery box if needed and still come out ahead. I don’t recall anyone mentioning those batteries here, or perhaps I just don’t remember it...however there are several of us with Battleborns. We also mostly used Progressive Dynamics PD4655LV that installs into the existing power center, the one in that kit may require fabrication to install it.

BattleBorn also has a “CPU” (battery management system, or BMS) in every battery...it cannot be replaced, but I’m not sure I can Invision why one would need to. They don’t seem to discuss what their “CPU” does, though I’ll be honest and say I didn’t peruse the site to look for more detail beyond the link you provided.

[daleyocum]

Just to make your life more complicated, most portable solar panels aren’t designed for Lithium. If you go that route make sure ours does. The charging voltages for lithium are higher and knowing when they are done isn’t so obvious. I suspect you’d want the panel to pump out a constant 14.5v for the Battleborn batteries and never decide to quit.

Has anyone seen a portable panel that will do that?

[gklott]

Originally Posted by uncle_bob

Hi
You toss up a batch of suggestions, ideas, thoughts, and present them all as if they are "the rules". That simply is not true and you are miss-representing the situation to anybody who does not do a lot of research.

Your statement is factually incorrect. Recommend reading NFPA 70, Article 690. Every item I recommend is there. Concerning the two pole solar disconnect switch, start with Section 690.13.

Originally Posted by uncle_bob

The most basic way to demonstrate that is the complete lack of any RV set up the way you suggest. You can go on all you want about "legal this and sue that". The manufacturers simply do *not* set up RV's the way you think they should be done.

As of 2018, the RVIA does not include solar (photovoltaics) as a power source for recreational vehicles in ANSI/RVIA LV section 2-1. The words "solar" and "photovoltaic" are not in the RV Industry's own low voltage standard. Why is that - given the recent 2018 update?

That explains "...the complete lack of any RV set up the way you suggest."

Until the RVIA standardizes photovoltaic power safety requirements, RV manufacturing methods will not change. Until then, our best guidance is NEC Article 690.

Originally Posted by uncle_bob

I (obviously) don't like FUD campaigns at all. That is very much what is going on here.

There is no fear, uncertainty, and disinformation in anything I recommend. It's the same guidance, what you call 'rules', that specifies 30A AC wiring should be at least 10 AWG. Is that FUD?

I hope ghaag finds this useful in expanding his solar installation. I wish them a safe and enjoyable experience with their solar expansion. Adding a solar energy power source to any Airstream is a meritable undertaking.

73/gus

[uncle_bob]

Originally Posted by gklott

Your statement is factually incorrect. Recommend reading NFPA 70, Article 690. Every item I recommend is there. Concerning the two pole solar disconnect switch, start with Section 690.13.



As of 2018, the RVIA does not include solar (photovoltaics) as a power source for recreational vehicles in ANSI/RVIA LV section 2-1. The words "solar" and "photovoltaic" are not in the RV Industry's own low voltage standard. Why is that - given the recent 2018 update?

That explains "...the complete lack of any RV set up the way you suggest."

Until the RVIA standardizes photovoltaic power safety requirements, RV manufacturing methods will not change. Until then, our best guidance is NEC Article 690.



There is no fear, uncertainty, and disinformation in anything I recommend. It's the same guidance, what you call 'rules', that specifies 30A AC wiring should be at least 10 AWG. Is that FUD?

I hope ghaag finds this useful in expanding his solar installation. I wish them a safe and enjoyable experience with their solar expansion. Adding a solar energy power source to any Airstream is a meritable undertaking.

73/gus

Hi

Ok, so *finally* we get to the point where you admit that these *are* simply "good ideas" and not something that *must* be done as a part of a set of laws governing RV's. Present them as "good ideas" and there's no FUD involved.

Bob

[InterBlog]

You are going to get lots of advice from lots of different people, advice which you then have to sift through as you zero in on your own system. These sources describe our system:

(1) Air Forums thread by my husband as OP "My Interstate lithium battery adventures"
(2) Part 1 of a blog series where I give a simplified system overview
(3) Part 2 of a blog series where I describe the AC system
(4) Parts 3 and 4 summarizing charging and DC systems are still forthcoming

We didn't "go to the max" on what we could do, but we did size it for some atypical requirements, such as the running of my off-grid office. 300 watts solar, 300 AH lithium, 4-way battery charging. Here's a diagram of part of it:

[ghaag]

Originally Posted by InterBlog

You are going to get lots of advice from lots of different people, advice which you then have to sift through as you zero in on your own system. These sources describe our system:



(1) Air Forums thread by my husband as OP "My Interstate lithium battery adventures"

(2) Part 1 of a blog series where I give a simplified system overview

(3) Part 2 of a blog series where I describe the AC system

(4) Parts 3 and 4 summarizing charging and DC systems are still forthcoming



We didn't "go to the max" on what we could do, but we did size it for some atypical requirements, such as the running of my off-grid office. 300 watts solar, 300 AH lithium, 4-way battery charging. Here's a diagram of part of it:

Thank you so much for the information, I look forward to reading thru it!

[mythbuster88]

Originally Posted by gklott

For your system, recommend closely following the requirements specified in NFPA-70, National Electrical Code, and the ANSI/RVIA LV. Don't skip any details in NEC Article 690. Life-Safety items commonly left out of RV solar installations include:
1. Fuses in each solar panel string.
2. Roof-top combiner box and all other devices being listed for the specific use (e.g., UL, ETL, PS)
3. A two-pole disconnect switch in the circuit from combiner box to charger. This switch should be readily accessible from the outside for first responder use.
4. A DC ground fault protection device (GFPD) just before the solar charger. A few solar chargers have this built in.
5. Proper warning and function labeling.
6. Plenty of ventilation for the charger, inverter, etc.

Design in safety, install safely, and maintain for a safe RV.

73/gus

Thanks for that! On my experimental solar setup I have no switch between panels and controller, just a 30A fuse! OOPS

[Jayd]

We are switching out our 2 AGMs (and having appropriate converter switched in as well) for 2 Battle Borns. Considering having the Airstream dealer move the batteries from outside box to under our front bed.
Is this safe?

[Troutboy]

Originally Posted by Jayd

We are switching out our 2 AGMs (and having appropriate converter switched in as well) for 2 Battle Borns. Considering having the Airstream dealer move the batteries from outside box to under our front bed.

Is this safe?

Yes, lithium inside is preferred and safe. They do not emit gases like lead acid.

[uncle_bob]

Hi

Preferred ... well as with everything else about an AS that is a "that depends" sort of thing.

The big reason to move them indoors is to keep them warm in the winter. There are two sides to that. Keeping them warm in storage and keeping them warm in use. On the storage side, indoors is likely the same as outdoors. On the use side, indeed indoors should be warmer.

The question then becomes - will you be out and about with the batteries continuously below 24F all day long? That's pretty darn cold for an AS. Most of us pack up before that part of the season hits

The battery box on modern AS trailers is a grubby / dirty / wet location. It works for batteries, but not for much else. It's also a real pain to get to. If you don't use it for batteries, there's not a lot else it is use-full for. Storage is at a premium in any trailer so using it wisely is a big deal ....

Lots of tradeoffs ....

Bob

[ROBERT CROSS]

If your battery box is on the tongue, move them.
There is no way to keep the moisture out.
The box is for storage on our Classic. I finally gave up and just drilled the bottom and lined with drainage tiles.

Remember you are basically storing a potential heat source, don't crowd them.

We access our batt's from the outside but the "boxes" are actually inside under the front couch. Dry, secure and vented.

Bob
🇺🇸

[Paprika]

"The battery box on modern AS trailers is a grubby / dirty / wet location. It works for batteries, but not for much else. It's also a real pain to get to. If you don't use it for batteries, there's not a lot else it is use-full for."

I store a bunch of Lynx leveling blocks, some smelly rubber chocks, and extra butane canisters for a portable stovetop in my former battery box. Since my 27FB with queen bed has minimal outside storage, that's a very useful thing for me. I installed my lithium batteries and other electrical gear under the bed.

[ROBERT CROSS]

^
YEP...storage only. 😂

Bob
🇺🇸

[switz]

The battery box on our 2014 31' Classic is the home for the hydraulic disk brake pump and associated parts. On our 2015 23D, the battery box has the wheel chocks and stabilizer plastic pads.

The Classic's 600 amp hour lithium battery is under the front soda curb side while the 23D 300 amp hour lithium battery is under the sofa just in front of the street side wheel well.

[ROBERT CROSS]

...others more informed than I may find it boring.

https://www.youtube.com/watch?v=s64CuK5Yy_o

Bob
🇺🇸