Replace 12v battery with Power Station

[greglarious]

Owner of a 2023 XLS 22 MLE looking at the Bluetti AC200L with their D40 attachment.

Kicking around the idea of entirely removing the existing 12v battery, solar charge controller, and charger connection from the WFCO to the 12v battery and replacing it with the power station.

Here is the idea:
- remove the old 12v parts
- mount the Bluetti AC200L in a locking metal tongue box
- Mount 1 Bluetti extension battery in the metal box bringing capacity up to 5kwh
- Mount the Bluetti D40 in the metal box and connect it to same wires that used to connect to the 12v lead acid battery
- Remove the charging connection from the WFCO to the 12v battery (don't want the RV trying to charge the Bluetti via 12v)
- Connect roof solar to Bluetti charging input (maybe add more solar panels or swap out panels)

Boondocking Use:
- Connect shore power plug from back of the RV up to the Bluetti 120v 30amp plug
- All RV 12v needs come from the DC output of the Bluetti via the D40
- All RV 120v needs come from the Bluetti sinewave inverter
- Solar panels charge Bluetti directly

On-grid use:
- Connect shore power plug from back of the RV to the campground outlet
- If solar does not charge Bluetti enough, can also plug the Bluetti AC charging port into campground AC
- Can I disconnect the Bluetti and run all RV 12v from shore power?

Pros:
- Battery/inverter/solar charger as one app-controlled tested, expandable unit
- Eliminate weight and complexity of multiple battery systems
- Eliminate energy loss charging one battery from another
- Not too much rewiring for a DIY project
- Bluetti and extra battery can be easily lifted out any time for storage or use in other places

Cons:
- The 2400W Bluetti inverter might not be enough to run the AC but who runs an AC off of a battery anyway?
- Seems silly to have that shore power plug run from the back of the RV to plug into the Bluetti at the front of the RV
- Still working out how to safely let shore power provide 12v instead of the Bluetti

Questions:
- Is the Bluetti D40 12v output at 20A max enough to drive normal RV 12v needs?
(edit: the answer is apparently not. The tongue jack alone says it needs 30A. Still want to know what the practical max is)
- How to safely switch RV 12v needs from Bluetti to shore power?
- How to make sure the WFCO never sends power into the Bluetti 12v output connection?
- How to make sure both shore 12v power and Bluetti 12v power are never active at the same time?
- Will the Bluetti be safe enough from weather/moisture/overheating in a metal box on the tongue?
- Will the Bluetti app be able to talk to it while it's inside of a metal box or will that be essentially a Faraday cage? (Is a plastic box safe enough?)

Is there some fundamental concept I am missing here?
Is there a safety concern with any of this?

 

[robmcqueen]

Owner of a 2023 XLS 22 MLE looking at the Bluetti AC200L with their D40 attachment.

Kicking around the idea of entirely removing the existing 12v battery, solar charge controller, and charger connection from the WFCO to the 12v battery and replacing it with the power station.

Here is the idea:
- remove the old 12v parts
- mount the Bluetti AC200L in a locking metal tongue box
- Mount 1 Bluetti extension battery in the metal box bringing capacity up to 5kwh
- Mount the Bluetti D40 in the metal box and connect it to same wires that used to connect to the 12v lead acid battery
- Remove the charging connection from the WFCO to the 12v battery (don't want the RV trying to charge the Bluetti via 12v)
- Connect roof solar to Bluetti charging input (maybe add more solar panels or swap out panels)

Boondocking Use:
- Connect shore power plug from back of the RV up to the Bluetti 120v 30amp plug
- All RV 12v needs come from the DC output of the Bluetti via the D40
- All RV 120v needs come from the Bluetti sinewave inverter
- Solar panels charge Bluetti directly

On-grid use:
- Connect shore power plug from back of the RV to the campground outlet
- If solar does not charge Bluetti enough, can also plug the Bluetti AC charging port into campground AC
- Can I disconnect the Bluetti and run all RV 12v from shore power?

Pros:
- Battery/inverter/solar charger as one app-controlled tested, expandable unit
- Eliminate weight and complexity of multiple battery systems
- Eliminate energy loss charging one battery from another
- Not too much rewiring for a DIY project
- Bluetti and extra battery can be easily lifted out any time for storage or use in other places

Cons:
- The 2400W Bluetti inverter might not be enough to run the AC but who runs an AC off of a battery anyway?
- Seems silly to have that shore power plug run from the back of the RV to plug into the Bluetti at the front of the RV
- Still working out how to safely let shore power provide 12v instead of the Bluetti

Questions:
- Is the Bluetti D40 12v output at 20A max enough to drive normal RV 12v needs?
- How to safely switch RV 12v needs from Bluetti to shore power?
- How to make sure the WFCO never sends power into the Bluetti 12v output connection?
- How to make sure both shore 12v power and Bluetti 12v power are never active at the same time?
- Will the Bluetti be safe enough from weather/moisture/overheating in a metal box on the tongue?
- Will the Bluetti app be able to talk to it while it's inside of a metal box or will that be essentially a Faraday cage? (Is a plastic box safe enough?)

Is there some fundamental concept I am missing here?
Is there a safety concern with any of this?

Why do you want to do this ? Having a power station and plugging the trailer into it when boondocking is not a bad idea. Just flip the breaker for the converter. Also might want to look at the Ecoflow units They have one model that you can recharge it a EV charging station

 

[greglarious]

Did you see the various pros listed above?
There are a lot of inefficiencies to preserving the old 12v system. Seems best to just let the old stuff go away permanently.

In general, the technology and market demand for power stations is fueling a massive leap forward and cost reduction.

 

[jkwilson]

Did you see the various pros listed above?
There are a lot of inefficiencies to preserving the old 12v system. Seems best to just let the old stuff go away permanently.

In general, the technology and market demand for power stations is fueling a massive leap forward and cost reduction.

There are no pros. It’s a tiny battery, less than half the size of what is normally used in even a basic RV electrical system that costs more than implementing the same functionality inside the RV..

 

[greglarious]

I'm not here to convince anyone else this is a good idea. More interested in learning what technical aspects I might be missing in how to get this together safely or how it will perform once installed.

There are no pros. It’s a tiny battery, less than half the size of what is normally used in even a basic RV electrical system that costs more than implementing the same functionality inside the RV..

I see you having an issue with my list of pros and I'll translate that statement as "they do not match your priorities".
The reasons for each pro I listed are technically valid and for me they do matter.

With the expansion battery the Bluetti at 5kwh is equivalent to 416ah of 12v LIFEP04 batteries.
Are people really putting > 832ah of LIFEPO4 into their RVs? I am unsure of the benefit of this. For my purposes we can be frugal with power and that 5kwh will comfortably last 4 days with zero solar charging. Depending on solar investment that could be extended easily to fit my needs.

Here is a cost analysis of a full RV style LIFEP04 system versus a Power station style solution.
I am leaving solar panels off of this as there is no difference in specifications for solar between the two paths.

Classic RV components (I like Renogy and I realize the cost varies with other brands)
$1400 - 2 Renogy 12v 200Ah battery
$370 - 1 Renogy 3000W sine wave inverter (Sits in between the Bluetti's 2400W steady and 3600W power lifting mode)
$370 - 1 Renogy 60 Amp MPPT Solar Charge Controller (Closest to the 1200W controller on the Bluetti)
(assuming the WFCO-8735 does not need to be replaced)
----------
$2140 Total

$1300 - 1 Bluetti AC200L + 2x200W 12v solar
$1600 - 1 Bluetti AC300 3kwh expansion battery
$200 - 1 Bluetti D40 DC-to-DC unit
----------
$3100

The cost difference is roughly $1000 premium so obviously cost is not one of the pros.
However, these solutions are not equivalent. With the Power center, you get metrics and fine control from a single app for so many things.
The time and parts to integrate the separate RV components also has cost in both time and money, as well as some degree of frustration.

For an average person without electrical skills, weighing the simplicity of a DIY drop-in project versus paying a shop and waiting for an upgrade can be a real concern.

 

[traveldawg]

This is pretty novel idea. I suppose you can find some merit in it. There aren't many more pros than cons tho. And I think the pro about "...rewiring for DIY project..." is more of a con although any system might require wiring changes - so that's a 'wash".

I'm not sure what to make of "...eliminate weight and complexity of multiple battery systems..." either. Even if you used multiple batteries I would assume it is just one system of batteries to maintain.

Maybe another Con is that you have to find a box to put all that in and then rig up a way to mount it.

And, as you showed, a traditional approach is less costly. It would probably be more attractive to the next buyer too.

Just sayin'.... seems to a bit of a novel idea but not much more practical than a traditional battery approach. I have nothing against your plan. It just seems like extra work with little cost or usage benefit.

 

[huntindog]

I'm not here to convince anyone else this is a good idea. More interested in learning what technical aspects I might be missing in how to get this together safely or how it will perform once installed.



I see you having an issue with my list of pros and I'll translate that statement as "they do not match your priorities".
The reasons for each pro I listed are technically valid and for me they do matter.

With the expansion battery the Bluetti at 5kwh is equivalent to 416ah of 12v LIFEP04 batteries.
Are people really putting > 832ah of LIFEPO4 into their RVs? I am unsure of the benefit of this. For my purposes we can be frugal with power and that 5kwh will comfortably last 4 days with zero solar charging. Depending on solar investment that could be extended easily to fit my needs.

Here is a cost analysis of a full RV style LIFEP04 system versus a Power station style solution.
I am leaving solar panels off of this as there is no difference in specifications for solar between the two paths.

Classic RV components (I like Renogy and I realize the cost varies with other brands)
$1400 - 2 Renogy 12v 200Ah battery
$370 - 1 Renogy 3000W sine wave inverter (Sits in between the Bluetti's 2400W steady and 3600W power lifting mode)
$370 - 1 Renogy 60 Amp MPPT Solar Charge Controller (Closest to the 1200W controller on the Bluetti)
(assuming the WFCO-8735 does not need to be replaced)
----------
$2140 Total

$1300 - 1 Bluetti AC200L + 2x200W 12v solar
$1600 - 1 Bluetti AC300 3kwh expansion battery
$200 - 1 Bluetti D40 DC-to-DC unit
----------
$3100

The cost difference is roughly $1000 premium so obviously cost is not one of the pros.
However, these solutions are not equivalent. With the Power center, you get metrics and fine control from a single app for so many things.
The time and parts to integrate the separate RV components also has cost in both time and money, as well as some degree of frustration.

For an average person without electrical skills, weighing the simplicity of a DIY drop-in project versus paying a shop and waiting for an upgrade can be a real concern.

See my sgnature as to what I did.
I do not see the attraction of all these Solar genertor/Power centers
All they are is a battery with the ability to be charged via solar or Shore power. Same as the RV....In my case the RV also has an actual 5.5KW gas powered generator
Do what you want, But someday your will want to sell it, and as with any off the wall mod done to to any item it will decrease the price and marketability of your RV.

 

[trailrydr]

Like the OP, our comfort during our time on the road may or may not align with others. Besides, some dont plan on getting a lot of money out of a shoebox after wearing the shoes for a period of time.

So, if it works for the OP Im sure it will have its benefits.

 

[huntindog]

Like the OP, our comfort during our time on the road may or may not align with others. Besides, some dont plan on getting a lot of money out of a shoebox after wearing the shoes for a period of time.

So, if it works for the OP Im sure it will have its benefits.

You sell used shoes?
Seriously, comparing shoes to an RV is ridiculous.
Shoes can be bought with walking around money. RVs, not so much. They are a MAJOR expense.
I have recieved above market prices for all of my previous RVs. The first person to view them buys them.
I know from buying my first used RV that there are a LOT of cobbled together modded trailers out there. I looked at dozens for about 5 minutes until I walked into the one that stood out from the crowd. I knew immeadiatly that it was the one. I had to go over my budget to get it,,but it was so much better than the junk I had seen that it was an easy decision.

When it is time to sell RESALE price matters.

 

[trailrydr]

You sell used shoes?
Seriously, comparing shoes to an RV is ridiculous.
Shoes can be bought with walking around money. RVs, not so much. They are a MAJOR expense.
I have recieved above market prices for all of my previous RVs. The first person to view them buys them.
I know from buying my first used RV that there are a LOT of cobbled together modded trailers out there. I looked at dozens for about 5 minutes until I walked into the one that stood out from the crowd. I knew immeadiatly that it was the one. I had to go over my budget to get it,,but it was so much better than the junk I had seen that it was an easy decision.

When it is time to sell RESALE price matters.

No..... not to everybody. And the way these things are built, IMO I dont expect it to hold a lot of value when I get ready to sell it.

 

[Scott'n'Wendy]

I'm not here to convince anyone else this is a good idea. More interested in learning what technical aspects I might be missing in how to get this together safely or how it will perform once installed.

I'm not sure what you gain here, although portability would be one for sure. Like if you have another place to make use of it, it will be easy to pick up and move. But that portability means the battery is small so you will likely have to buy more battery to make it useful for more than a couple days in the RV.
If I understand correctly, the Bluetti is a battery, a converter, a solar charge controller, and a bluetooth transmitter all packaged inside a portable box?

 

[BoredWeasel]

It is a very expensive solution. You are further ahead adding lithium batterys and a bigger inverter if you want. so you are looking at 400 amp hours of lithium, ballpark about $1400 in batterys and probabably another $500 bucks for an inverter. The power station combo your looking at is probabaly $3k or more.

The biggy for me is if any aspect of the the power station fails you are SOL, time to buy a new one. battery gets week new power station, inverter fails new power station, charger fails new power station.....you get my point.

I run my ac unit on battery from time to time.....it is great when stopping for lunch when traveling.

I would not put it in the tongue box or anywhere with significant changes in temperature. I imagine moisture/condensation will be an issue.

 

[huntindog]

No..... not to everybody. And the way these things are built, IMO I dont expect it to hold a lot of value when I get ready to sell it.

RV #1 , A 1975 Prowler 24'. paid 2300.00 sold 3200.00(I installed a generator in it) #2 A 2001 Fleetwood Wilderness 27'. Paid 15,500.00 new, sold in 2010 9500.00. #3 A 2010 Palomino Sabre[ 34', Paid 24,000.00 new sold in 2020 for 16,000.00. #4 . The Momentum in my signature. Paid 105,000.00. Sold TBD later.

As my story shows I was able to get pretty good money for units I used for 10 years. Those good prices allowed us to upgrade to the unit we wanted everytime.
So unless your present unit is your last. Money will matter

"No you protest it doesn't"
So then, you would sell it for $5.00 , if that was the best offer you could get?......Obviously Money matters.
Money Even if it is your last RV, ALWAYS matters.

 

[Soundsailor]

Let's try to keep this thread on topic. The resale value does not relate to the OP's original question.