Plan for Lithium and Solar upgrade

[TowmaterATX]

Originally Posted by solomon.m

I like everything in your shopping list but would have a look at an automatic transfer switch. AM Solar described a "Smart-ATS" switch in some of their installs where the switch is automatic and controls on the MPPT let you tune how much draw is coming from shore power and letting the balance come from onboard sources. Here is a link to a wiring diagram from one of their kits
https://drive.google.com/drive/folde...C1YbLzdNrrT32E

Following this thread now as I'm looking at a similar install

I looked at the Smart-ATS, but decided I'm fine with a manual switch to get the same thing. That's what the transfer switch in my diagram does. I believe it does exactly the same function as the Smart-ATS but not automatically. And it was quite a bit cheaper. If the Smart-ATS does more than what my switch is doing, I'd love to understand what other functions it has.

[Sidwar]

TOW this thread may help with the Dometic Q.

https://www.airforums.com/forums/f44...ll-207106.html

[GMFL]

Originally Posted by TowmaterATX

How much current can you pull from your TV with this setup? This does sound interesting, but I'm not sure I'll need it depending on how many panels I can pack onto the roof. But this does seem like it might be a good use of the battery cables running to the front of the trailer since the LiFePOs will be inside.

My system with Losses charges at 48.5A.

[jimdelane]

Your drawing looks good. You might reconsider your choice of batteries. The BattleBorn have a 100Amp BMS and you will need to wire them together in parallel to get 300Ah. Unlike lead acid batteries, these batteries independently handle charge/discharge with the BMS.
You might consider purchasing a single 300Ah or 400Ah battery with a stronger BMS.
(3) BattleBorn 100Ah batteries require a space 12.75" x 20.5"
The 300ah or 400ah batteries are 8D which is 10.5" x 20.5"
Depending on the manufacturer - the 300ah or 400ah can have a 150A, 200A or 300A BMS. The end result is a smaller battery with less connections and less things to go wrong. The stronger BMS will handle the possible multiple loads better. Remember 1A@120V = 10A@12V.

As an example - Sharp 1000W Microwave Oven
https://www.cnet.com/products/sharp-...ve-oven-black/
Rated Current= 15 A @ 120v
Max Power Consumption = 1530 Watt
(watts = volts x amps) 1530w = 127.5A x 12V
To run this with an inverter - you will use 127.5A @ 12V. All BMS have the ability to exceed the BMS rating for a short period, then the battery turns off. However, this stresses the BMS since it is designed to safely function at 100A and can lead to failure.

I also think that you should consider a DC-DC charger per GMFL post. The problems with depending on panels is shade and bad weather. Also solar panels never put out rated watts due to sun angle, etc. You can expect 50-75% of rated output.

Possible lithium battery sources:

AMPS Lithium
https://lithiummarinebattery.com/shop

LiFeBlue Battery
http://www.lifebluebattery.com

ReLion
https://relionbattery.com/products/lithium

SmartBattery
https://www.lithiumion-batteries.com...-rv-deep-cycle

[pcskier]

Originally Posted by TowmaterATX

Thanks. Once I get eyes on the trailer I'll figure out if pulling more wire makes sense. The panels I've been looking at are just over 20V and just under 5A at full power. So part of me thinks that a little bit of loss if they are all at 100% vs the potential for more loss in the more common case of partial shading with a series-parallel is a tradeoff that makes sense. But I hear you, if I can run the wires easily... no need to choose.

Have a look at the "Solar Show and Tell" thread on this forum. A member called "Airmiles" has his panel set up series/parallel to take advantage of the prewire, and he has documented results posted there, which are excellent. My personal preference is full parallel if possible, and if doing all this work, fatter wire to get the most from the system. Some trailers it's a piece of cake, others a little more involved but worth it. I am going to guess that on your new 25 footer, the easiest routing would be through the fridge vent on the roof, without having do drill through the roof.

[TowmaterATX]

Originally Posted by pcskier

Have a look at the "Solar Show and Tell" thread on this forum. A member called "Airmiles" has his panel set up series/parallel to take advantage of the prewire, and he has documented results posted there, which are excellent. My personal preference is full parallel if possible, and if doing all this work, fatter wire to get the most from the system. Some trailers it's a piece of cake, others a little more involved but worth it. I am going to guess that on your new 25 footer, the easiest routing would be through the fridge vent on the roof, without having do drill through the roof.

I pick it up Wednesday so I can start looking then. But I think all the new 2021 GT have compressor fridges. Which was also one of the reasons I wanted to go with LiFePO batteries. If it's easy enough to run, I should have some 6 AWG wire left from the spools I bought for the rest of my upgrade. Then I could look at more panels.

[TowmaterATX]

Originally Posted by jimdelane

The BattleBorn have a 100Amp BMS and you will need to wire them together in parallel to get 300Ah. Unlike lead acid batteries, these batteries independently handle charge/discharge with the BMS.
You might consider purchasing a single 300Ah or 400Ah battery with a stronger BMS.

I did look around. The problem is just knowing what would fit and where. I figured with smaller batteries I could line them up different and give myself some options for location. I couldn't find any good pictures of under the beds for the new 2021 GT FBT to know what would work well there. Plus, I called them and they offered a pretty good discount on the phone. I'd recommend calling them vs buying from the web store.

The trailer doesn't have the solar option which means it will not have any batteries. I wanted to save the money on buying lead batteries and jump straight to the Lithium so I wanted to order before I had hands on the trailer.

[daleyocum]

Originally Posted by solomon.m

I like everything in your shopping list but would have a look at an automatic transfer switch. AM Solar described a "Smart-ATS" switch in some of their installs where the switch is automatic and controls on the MPPT let you tune how much draw is coming from shore power and letting the balance come from onboard sources. Here is a link to a wiring diagram from one of their kits
https://drive.google.com/drive/folde...C1YbLzdNrrT32E

Following this thread now as I'm looking at a similar install

The Victron Multiplus handles all that mixing of shore power and battery power so in this case you don’t need a transfer switch.

[daleyocum]

Originally Posted by TowmaterATX

I have the Champion 3400W dual fuel. Running it on propane I should be about to get ~2800W continuous out of it. If I can get another 200-300W of solar and use the multi to add hybrid power when both compressors kick on at the same time, I suspect I'll be okay. But I need to measure the average load and that's doing to depend on the duty cycle. I suspect full sun on your Texas day in August may not work, but we'll see.

I didn't know about the soft start on the 2021s already being there. I ordered two microair easy starts. Anyone know if the the 2021 ACs do in fact have a factory easy start? Is that factor easy start any good?

The point is I doubt the Multiplus will be happy about driving two ACs. That would imply that you rewire it so both ACs are on the same 30amp leg which is not the way it comes stock because it’s too much current.

What I was saying is have one AC go though the Multiplus, which is fed by one of the legs out of your generator, and the other leg of your 50amp connector comes directly from the generator and drives the second AC with no hybrid assist. You’d only be able to use the second AC when on either the generator or 50a shore power. I’m uncertain about the Champion running both ACs continuously but time will tell. My Honda 2000 had to really work at running just one before the Multiplus.

Keep in mind generators on propane produce less power than on gas. I’m not sure the reduction, I’m guessing 10%.

Here’s the thread on the new ACs having a built in soft start. https://www.airforums.com/forums/f44...ll-207106.html

[TowmaterATX]

Originally Posted by daleyocum

The point is I doubt the Multiplus will be happy about driving two ACs.

From the service manual for the Multiplus:

AC-out-1 (see appendix A)
The AC output cable can be connected directly to the terminal block "AC-out".
From left to right: “PE” (earth), “N” (neutral) and “L” (phase). The Output Neutral is not bonded to ground.
With its PowerAssist feature the Multi can add up to 3kVA (that is 3000 / 120 = 25A) to the output during periods of peak power
requirement. Together with a maximum input current of 50A this means that the output can supply up to 50 + 25 = 75A.
An earth leakage circuit breaker and a fuse or circuit breaker rated to support the expected load must be included in
series with the output, and cable cross-section must be sized accordingly. The maximum rating of the fuse or circuit breaker
is 75A.

Which I think means that if my generator is producing 2800W and then the multi can add another 3kW and I could have 5.8kW outbound on AC1. Which would mean I was at 48A 120VAC. I wouldn't want to push it all that hard, but I think I should be able to run 30A continuous load with occasional bursts above that when the compressors start.

Originally Posted by daleyocum

Here’s the thread on the new ACs having a built in soft start. https://www.airforums.com/forums/f44...ll-207106.html

Thanks for the link to this thread. It looks like on page 4 that there is some confusion if the new units actually have this system (at least on the new Airstream trailers). I'll take my shroud off and try to install the two micro airs that I ordered when I get the trailer and the microairs (maybe this weekend) and I'll report back to the thread.

[TowmaterATX]

Originally Posted by TowmaterATX

Which I think means that if my generator is producing 2800W and then the multi can add another 3kW and I could have 5.8kW outbound on AC1.

This makes me think I need to run two 6AWG from Multiplus' AC-out-1 Line to each of the terminals on my transfer switch as well as two 6 AWG to the neutral bus on the stock panel.

If I just ran one 6 AWG to the transfer switch and jumpered the other line output with 6AWG, I could exceed the load limits on the first wire with the draw from both legs in the panel. Things could get hot.

Since the Multi can put out 75A total in this configuration I should make sure I run 6 AWG to both line terminals on my transfer switch since neither of them can draw more than 50A due to the main breaker. And if I double up the 6AWG for the neutral I get an effective 3 AWG which is fine for the short run at 75A. I'll have to update my drawing. Better safe than sorry. Makes me wonder how many people just assume the Multiplus will stop at 50A and only have 6 AWG connected to AC-out-1.

[solomon.m]

Originally Posted by TowmaterATX

I looked at the Smart-ATS, but decided I'm fine with a manual switch to get the same thing. That's what the transfer switch in my diagram does. I believe it does exactly the same function as the Smart-ATS but not automatically. And it was quite a bit cheaper. If the Smart-ATS does more than what my switch is doing, I'd love to understand what other functions it has.

Have a look at this video on Youtube comparing the manual and auto switch.
https://youtu.be/7xKOyRyxdNk
Benefits are the auto sensing of what is coming in and how to best route the power for max usage. I'm a fan of reducing the human error and having to explain one more switch to my partner in crime

[daleyocum]

Originally Posted by TowmaterATX

This makes me think I need to run two 6AWG from Multiplus' AC-out-1 Line to each of the terminals on my transfer switch as well as two 6 AWG to the neutral bus on the stock panel.

If I just ran one 6 AWG to the transfer switch and jumpered the other line output with 6AWG, I could exceed the load limits on the first wire with the draw from both legs in the panel. Things could get hot.

Since the Multi can put out 75A total in this configuration I should make sure I run 6 AWG to both line terminals on my transfer switch since neither of them can draw more than 50A due to the main breaker. And if I double up the 6AWG for the neutral I get an effective 3 AWG which is fine for the short run at 75A. I'll have to update my drawing. Better safe than sorry. Makes me wonder how many people just assume the Multiplus will stop at 50A and only have 6 AWG connected to AC-out-1.

Once again, why is there a transfer switch in your design? That’s one of the things the Multiplus does.

Second, I’m not aware that the Victron works like that. I could be wrong but I don’t think you can draw more than the rated current from the unit, no matter whether it’s hybrid or 100% battery. If you find documentation to the contrary I’d be interested.

[TowmaterATX]

Originally Posted by daleyocum

Once again, why is there a transfer switch in your design? That’s one of the things the Multiplus does.

Second, I’m not aware that the Victron works like that. I could be wrong but I don’t think you can draw more than the rated current from the unit, no matter whether it’s hybrid or 100% battery. If you find documentation to the contrary I’d be interested.

Taken from Service-Manual-MultiPlus-3k-120V-(firmware-xxxx4xx)-EN-ES.pdf on the bottom of page 4. I bolded the relevant part:

[QUOTE]AC-out-1 (see appendix A)
The AC output cable can be connected directly to the terminal block "AC-out". From left to right: “PE” (earth), “N” (neutral) and “L” (phase). The Output Neutral is not bonded to ground. With its PowerAssist feature the Multi can add up to 3kVA (that is 3000 / 120 = 25A) to the output during periods of peak power requirement. Together with a maximum input current of 50A this means that the output can supply up to 50 + 25 = 75A. An earth leakage circuit breaker and a fuse or circuit breaker rated to support the expected load must be included in series with the output, and cable cross-section must be sized accordingly. The maximum rating of the fuse or circuit breaker is 75A.
[QUOTE]

That shows that the multi can send a max output of 75A on AC-out-1. 50A from shore and another 25A it adds with hybrid.

Understanding that, I put the switch in to accomplish the same thing that the Smart-ATS from AM solar does without the cost.

First, a level set on the situation. Putting this out there so I have it wrong someone can correct me.

For RVs the 50A shore power connection is actually 2 50A rated line inputs. Red and black in my drawing. The stock panel is also wired to take these two 50A circuits (the double pole 50A main breaker). When you are plugged into 50A shore you could theoretically draw 100A of 120VAC. Our trailers will likely never do that, but when you bump up to 50A you get two lines with the way the industry has gone with the connectors and the standard hookups at the pedestals.

Now, what happens when you put a 30A to 50A adapter on your shore plug? The adapter internally ties the 1 hot line on the 30A side of the adapter to both of the hot lines on the 50A side. This is why when you are on 30A you can still run everything in your trailer if you're careful not to exceed the current limit and pop the breaker on the pedestal. Same thing applies for the 15/20A to 50A adapters, they take the 1 hot line and tie it to both on the 50A side.

My transfer switch does the same thing as the adapters, but does it after the multiplus. How?

In position 1 I will have the full 100A available because both lines from the short plug are passed through to the distribution panel. Of course our trailers never pull this much.

In position 2, I ignore one of the hot leads from the 50A connection since it's the same as the other hot. I take the hot lead I didn't ignore through the multi and with the augmented power I could see 30A from shore + another 25A from the multi for a total of 55A available to the trailer. The transfer switch as I've wired it ties the output of the multiplus AC-out-1 to _both_ lines in the stock panel in position 2. This is the exact same thing that your 30A to 50A adapter does, but I'll end up with a possible 55A instead of 30A in the trailer.

All that being said, if my average draw on the 120VAC side is more than shore or generator + whatever I'm getting from solar, I'll be depleting my battery bank. But this does allow me to do things like run the microwave and one AC at the same time when on a generator or even 15A shore power. While the microwave is running whatever is missing from the generator/shore supply will be augmented from the batteries by the multi and when the microwave stops if there is excess generator/shore power it will put that back into the batteries.

At least this is how I understand this to work. I'm very thankful for this forum and these questions. I'm learning a lot through this process and I plan on documenting the install to pay it forward to this great community.

Does what I put above make sense daleyocum? I appreciate your questions and feedback.

[daleyocum]

Thats good to know that the Multiplus is additive like that. Since I just have a 30a system with a single AC I didn’t face a lot of the issues you’ve addressed. Please do report back how it goes.

Most people don’t do a second transfer switch like that. It seems clever though!

[GMFL]

Originally Posted by daleyocum

Thats good to know that the Multiplus is additive like that. Since I just have a 30a system with a single AC I didn’t face a lot of the issues you’ve addressed. Please do report back how it goes.

Most people don’t do a second transfer switch like that. It seems clever though!

Now most DO the SPS transfer switch.

[ROBERT CROSS]

Originally Posted by GMFL

Now most DO the SPS transfer switch.

OK...I'm ignorant why?
Are we using both at....Never mind my solar is portable.
I have manual folding SPSTS. KISS

Bob
🇺🇸

[Chuck Bye]

I have a 25FBT with 180 watt solar and two Air Conditioners on order and would like to have the best electrical upgrade so I do not need to start making upgrades upon delivery. My dealer and airstream customer support are of no help and I do not know how to contact Airstream engineering for competent answers. I know nothing about electricity. It seems I will need an upgrade to a premium 2000 watt sine inverter (retail cost $200), a 2000 watt CONVERTER (retail cost $200) 2 gauge wiring on trailer, heavy gauge wiring to tow vehicle, modified monitor and dealer installed solar batteries with some type of sticker. (no one at the dealer or airstream knows anything about the POWER PLUS OPTION and what are the pros and cons.)
Some marketing from airstream says I am buying a 6 sleeping unit with 3 way refrigerator and others say 4 person with only two way refrigerator. Which is it?
Wisconsin Chuck

[ASFC25_2019]

Originally Posted by Chuck Bye

I have a 25FBT with 180 watt solar and two Air Conditioners on order and would like to have the best electrical upgrade so I do not need to start making upgrades upon delivery. My dealer and airstream customer support are of no help and I do not know how to contact Airstream engineering for competent answers. I know nothing about electricity. It seems I will need an upgrade to a premium 2000 watt sine inverter (retail cost $200), a 2000 watt CONVERTER (retail cost $200) 2 gauge wiring on trailer, heavy gauge wiring to tow vehicle, modified monitor and dealer installed solar batteries with some type of sticker. (no one at the dealer or airstream knows anything about the POWER PLUS OPTION and what are the pros and cons.)
Some marketing from airstream says I am buying a 6 sleeping unit with 3 way refrigerator and others say 4 person with only two way refrigerator. Which is it?
Wisconsin Chuck

I have your dealership install it. You pay more, but it works great. Suppose your dealership is not able to do it. Contact bayareaairstream; they do fantastic work. That is the dealership where we purchase our Airstream, and they did all the add ons. Plus, the dealership has fixed any bugs that have come up with the new purchased Airstream. They are straightforward to deal with via email and on the phone. The service manager is Josh, and the technician is Nick. They did a fantastic job. Nick is the best Airstream has for knowledge and understanding of electrical work. I recommend getting them to do the work. Joel at Expion360 is excellent support too! They provide a 6-year warranty on the batteries.
I would look at :
1. Magnum MSH3012 Hybrid Inverter Charger
2. ME-ARC remote
3. Expion360 Batteries
4. Zamp solar panels.
Good luck Cheers.

[switz]

When using a male 50 amp plug pigtail with a 30amp power cable connection on the other end, only one of the 50 amp legs is connected. Joining the two 50 amp wires together would trip breakers