Portable solar generator vs custom install

[SunchaserV]

Originally Posted by gypsydad

Guess I am missing something here? What is the issue with just replacing the 2 12V lead acid batteries with Lithium and if needed, get a portable Lithium battery, like a Jackery or EcoFlow for "other" uses? Seems to me, this would be less work, and serve much broader long-term needs? 12V 100+AH Li batteries with built in BMS/Bluetooth are selling from Walmart and others with good warranties for less than $200/each these days with Blackfriday deals also...

Agree, but some have personal hobbies and interests that keep them busy and challenged.

Once out of the garage and away from benign weather, messing around with a bevy of portable solar panels on a wet, cloudy and windy day doesn't appeal to me.

[wmcneil]

Originally Posted by gypsydad

Guess I am missing something here? What is the issue with just replacing the 2 12V lead acid batteries with Lithium and if needed, get a portable Lithium battery, like a Jackery or EcoFlow for "other" uses? Seems to me, this would be less work, and serve much broader long-term needs? 12V 100+AH Li batteries with built in BMS/Bluetooth are selling from Walmart and others with good warranties for less than $200/each these days with Blackfriday deals also...

Yes, not integrating the solar generator removes the work to integrate it. I addressed what the advantages of integrating it are in an earlier post in this thread:

The 4000 is certainly usable without integrating it. The advantages to integrating it are: easier/faster startup/shutdown when using in the AS (no plugging/unplugging or moving the unit required), and better use of space by being able to locate the unit wherever makes best sense, while still preserving the ability to quickly remove the unit from the AS and use it elsewhere.

I don’t see any advantage in upgrading the 12V house batteries to lithium, as they provide input only to the 12VDC distribution. If more battery capacity were desired, it would make more sense to add an expansion battery to the solar generator, which would expand both AC and DC capacity. If it is necessary to retain a 12V house battery for supplying the breakaway switch, then just about any basic 12V battery would meet the need.

[uncle_bob]

Originally Posted by richard5933

Does the 4000 have a 12vdc output? Is it coming directly from the batteries inside the unit? If so, then it would probably qualify for use on the e-brakes.

Hi

The 12V output on all of these things is from a DC/DC that runs off the (maybe) 58V internal batteries. Like all the other fun in the unit, it can be enabled or disabled under software control. I don't think it qualifies in this case ...

Some examples from the devices I have here:

1) You do a firmware update. Everything shuts down as part of the up date. When it's done, you have to re-enable all the outputs you need. Since the DC/DC soaks up power, the default is to have it off.

2) There's a pesky timer way down in the 23 page of the settings. It overrides this and that. It shuts off the DC/DC after 24 hours.

3) There's a temperature sensor internal to the device. If it gets a bit warm, it shuts off the DC/DC. Our trailer when running down the road most certainly gets warm.

4) There's an app with buttons. Folks hit the wrong button .....

Since the solution is to just leave a "dedicated" battery in the battery box with the 7 pin charge wire attached, it's not a really tough issue to solve. There are tons of trailers out there that work that way.

The battery would need to be big enough to run the brakes for 30(?) minutes. Yes that's a long time. You could look up the number in the regulations. It might well be 15 minutes.

Bob

[Wazbro]

Originally Posted by uncle_bob

Hi

The 12V output on all of these things is from a DC/DC that runs off the (maybe) 58V internal batteries. Like all the other fun in the unit, it can be enabled or disabled under software control. I don't think it qualifies in this case ...

Some examples from the devices I have here:

1) You do a firmware update. Everything shuts down as part of the up date. When it's done, you have to re-enable all the outputs you need. Since the DC/DC soaks up power, the default is to have it off.

2) There's a pesky timer way down in the 23 page of the settings. It overrides this and that. It shuts off the DC/DC after 24 hours.

3) There's a temperature sensor internal to the device. If it gets a bit warm, it shuts off the DC/DC. Our trailer when running down the road most certainly gets warm.

Since the solution is to just leave a "dedicated" battery in the battery box with the 7 pin charge wire attached, it's not a really tough issue to solve. There are tons of trailers out there that work that way.

The battery would need to be big enough to run the brakes for 30(?) minutes. Yes that's a long time. You could look up the number in the regulations. It might well be 15 minutes.

Bob

A typical battery dedicated for just the emergency breakaway is just 5ah and cost about $16-$50. Some examples.
https://www.etrailer.com/dept-pg-Acc...V_Battery.aspx

[ROBERT CROSS]

Originally Posted by wmcneil

I have a 2011 FC 25FB that currently has no solar, no lithium, no inverter. I have replaced the factory converter with a Progressive Dynamics PD4655VL converter.

I have been thinking/researching a “portable” solar generator(EX: Anker, Bluetti, Yeti) and briefcase solar panel vs. a custom solar installation(EX: Victron/Battleborn). I am not sure that I will use the Airstream enough to justify the time/cost of a custom install. The advantages that I see of a solar generator is that the modifications to “install” it are much less, and it could be used for other uses such as charging my electric car, or as a backup generator for my house, etc. One disadvantage is that a suitcase type solar panel array is going to be probably less efficient/convenient than panels mounted on the roof of the AS.

I would be interested in feedback from anyone that has gone the solar generator route. Thanks in advance for your feedback.

The Honda 2000 generator was the first thing we bought when we got 'Cloudsplitter' in 2004.
I converted it to dual fuel and it's still going strong.


We tried a Goal Zero solar 'generator but sent it back.
Six years ago we got two 180W Zamp portable suitcase solar panels and converted to lithium batteries. SFSG.

Bob
🇺🇸

[uncle_bob]

Originally Posted by Wazbro

A typical battery dedicated for just the emergency breakaway is just 5ah and cost about $16-$50. Some examples.
https://www.etrailer.com/dept-pg-Acc...V_Battery.aspx

Hi

Yup, and they are mighty small.

Since the battery box is "just sitting there" and you already have batteries in it .... not sure that you even need to spend the $16.

If there's a need for the battery box space then putting in a SLA somewhere / anywhere would be the "spend more money" choice.

Another twist to this:

If you have an electric tongue jack, it may pull a bit of current and it might generate spikes. Those could be an issue for the DC/DC in the 4000. You might find you need to move it back to a "normal battery". In that case the 5AH SLA probably isn't going to be big enough.

A lot of solar gizmos are targeted at pretty modest current output. It's like any other DC/DC converter. The bigger it gets, the more it costs and the more idle power it uses up. There is a "to big" limit for them if you are designing a solar power station.

Bob

[wmcneil]

Originally Posted by uncle_bob

If you have an electric tongue jack, it may pull a bit of current and it might generate spikes. Those could be an issue for the DC/DC in the 4000. You might find you need to move it back to a "normal battery". In that case the 5AH SLA probably isn't going to be big enough.

A lot of solar gizmos are targeted at pretty modest current output. It's like any other DC/DC converter. The bigger it gets, the more it costs and the more idle power it uses up. There is a "to big" limit for them if you are designing a solar power station.

Bob

The 4000 12VDC output is rated at 30 amps max. As I posted earlier, the Goal Zero documentation that comes with the integration kit they sell describes a scenario where the DC output is driving all of the trailer 12V distribution. I do want to hear back from them about my question about putting a battery on that 12V distribution….It may be that isolating the 4000 12VDC output with an external DC/DC is a good idea for multiple reasons.

[Mollysdad]

Originally Posted by SunchaserV

Agree, but some have personal hobbies and interests that keep them busy and challenged.

Yep, that's me.
My current (no pun intended) project has a pair of Renogy 220 w. suitcases feeding a Victron MPPT controller, via various switches and connectors to keep my old fashioned batteries charged. After much head scratching, all the hardware will be mounted a rack case intended for musicians. I worry it will walk away, but I couldn't see running all the cables back and forth inside. Until I drill the first hole, everything is flexible.

Once out of the garage and away from benign weather, messing around with a bevy of portable solar panels on a wet, cloudy and windy day doesn't appeal to me.

In my fantasy, my solar project will always be in sunshine, and provide endless free power.

[Wazbro]

Originally Posted by wmcneil

The 4000 12VDC output is rated at 30 amps max. As I posted earlier, the Goal Zero documentation that comes with the integration kit they sell describes a scenario where the DC output is driving all of the trailer 12V distribution. I do want to hear back from them about my question about putting a battery on that 12V distribution….It may be that isolating the 4000 12VDC output with an external DC/DC is a good idea for multiple reasons.

That 30 amp max is interesting, my TV has a 40 amp fuse for operating the trailer brakes.

[uncle_bob]

Hi

30A at 12V is only 360W. There are a *lot* of things here and there that pull a hundred watts (8A) or more. There are a few that likely go over 400W. There are also combinations that easily break that limit.

In this case 30A is indeed "low current".

Does all this stuff *average* hundreds of watts of drain? Nope. Most of it is intermittent loads that average out to something modest. The gotcha is when several just happen to come on at once or when you find that gizmo that pulls a lot of current under "this" condition.

Quick way to spot what's what: take a look at the 12V fuses and breakers. Anything over 15A is worth digging into.

The main DC distribution cabling and breakers are set up for 50A for a pretty good reason ( and the inverter goes past all that for a very good reason as well ...).

Again, I'm not saying don't do this. The only point here is that it does need to be done right. One very quick / simple answer it to put in a DC / DC "charger" converter on that 30A output and keep some batteries around. You will have the same issue with surge current as everybody else does. That will mean a bit of a deep dive on that DC/DC.

Bob

[wmcneil]

I heard back from the folks at Goal Zero. In order to obtain 12VDC output from the Yeti Pro 4000, it must be turned on, either by pressing a physical button, or
by using the app....I also asked about adding an external battery on the 12VDC distribution (to provide a failsafe against human error, for the breakaway switch), and using a DC/DC converter on the 4000 output to isolate it from the external battery and the rest of the DC distribution. I got no negative feedback from Goal Zero on that approach. They said it was not necessary, which I took to mean that their view was that adding the external battery was not necessary.....I'm not going down the rabbit hole of whether the external battery is legally required or not. Instead I'm thinking through the "external battery plus DC/DC converter" scenario some more and working on a wiring diagram.

[uncle_bob]

Originally Posted by wmcneil

I heard back from the folks at Goal Zero. In order to obtain 12VDC output from the Yeti Pro 4000, it must be turned on, either by pressing a physical button, or
by using the app....I also asked about adding an external battery on the 12VDC distribution (to provide a failsafe against human error, for the breakaway switch), and using a DC/DC converter on the 4000 output to isolate it from the external battery and the rest of the DC distribution. I got no negative feedback from Goal Zero on that approach. They said it was not necessary, which I took to mean that their view was that adding the external battery was not necessary.....I'm not going down the rabbit hole of whether the external battery is legally required or not. Instead I'm thinking through the "external battery plus DC/DC converter" scenario some more and working on a wiring diagram.

Hi

It's not just the 12V that works that way. I use some of these as UPS devices here at home. They (none of them) don't re-start when power comes back on. Yes, that's a bit of a pain (assuming the power has been out long enough that they have run out of power and shut down ...).

For the brake stuff, there's no real need for a DC/DC. Just put the battery on the charge wire from the 7 pin and you are good to go. The break away battery pretty much never is discharged. Even a 1A charge current through the 7 pin will keep it very happy.

Bob

[richard5933]

This 'simple' system setup seems to be getting more complicated all the time. The portable unit was replacing the trailer's batteries, and now another battery has to be installed to take its place to serve the e-brake system.

Still not sure how this is simpler than just installing an inverter and solar charge controller to the trailer. Use it with the stock batteries until the budget allows for lithium, and keep the portable unit at home if it's needed there for power outages.

Or, outfit the trailer with a decent lithium battery bank and use its system to power the house if the power goes out while it's parked in the backyard.

I know quite a few guys with vintage bus conversions that have wired a power-out connection so that they can use their buses as backup power supplies for the house - some use the onboard diesel generator to do this and others use the rooftop solar and battery bank to provide 120 (or 240) power through the onboard inverter.

I still don't see how re-configuring a trailer around one of these portable units makes more sense than doing a proper upgrade to the trailer's onboard systems. Using it as an auxiliary unit by plugging in through the shore power cord makes sense, but not doing a full re-configure like is being described above.

[BikeCamper]

Originally Posted by richard5933

This 'simple' system setup seems to be getting more complicated all the time. The portable unit was replacing the trailer's batteries, and now another battery has to be installed to take its place to serve the e-brake system.

Still not sure how this is simpler than just installing an inverter and solar charge controller to the trailer. Use it with the stock batteries until the budget allows for lithium, and keep the portable unit at home if it's needed there for power outages.

Or, outfit the trailer with a decent lithium battery bank and use its system to power the house if the power goes out while it's parked in the backyard.

I know quite a few guys with vintage bus conversions that have wired a power-out connection so that they can use their buses as backup power supplies for the house - some use the onboard diesel generator to do this and others use the rooftop solar and battery bank to provide 120 (or 240) power through the onboard inverter.

I still don't see how re-configuring a trailer around one of these portable units makes more sense than doing a proper upgrade to the trailer's onboard systems. Using it as an auxiliary unit by plugging in through the shore power cord makes sense, but not doing a full re-configure like is being described above.

Absolutely agree here. When I read through this thread the other day I had two main thoughts: (1) This is a needlessly complicated solution in search of a problem; and (2) Yikes - - hopefully he is planning to keep this trailer indefinitely because this is going to tank the resale value.

[gypsydad]

Originally Posted by BikeCamper

Absolutely agree here. When I read through this thread the other day I had two main thoughts: (1) This is a needlessly complicated solution in search of a problem; and (2) Yikes - - hopefully he is planning to keep this trailer indefinitely because this is going to tank the resale value.

I too, agree with you and Richard...some folks over think things!

[wmcneil]

For those who think that what I am proposing is getting too complicated for a "simple install of an all-in-one unit": I am retaining the ability to easily unplug and remove the Yeti power station/solar generator and use it elsewhere. If you don't care about this ability, then the extra work may not make sense to you. (But it is still a lot less work than a full DIY installation with all discrete components).

On the other hand, if this topic is still of interest, I have opened a new thread with detailed wiring diagrams for what I am planning for the Yeti Pro 4000:

https://www.airforums.com/forums/f44...ml#post2762684

[wmcneil]

Originally Posted by BikeCamper

(2) Yikes - - hopefully he is planning to keep this trailer indefinitely because this is going to tank the resale value.

Quite the opposite, actually. My approach will allow me to remove the Yeti power station and return the trailer to identical from-the-factory functionality. If I chose to do this when selling the trailer, my total sunk cost will be about $400 (assuming I stay with only portable solar panels), and I retain the Yeti. If the new owner wants to install a Yeti, they plug it in, turn a few switches, and have the full solar/inverter functionality.

[uncle_bob]

Originally Posted by wmcneil

Quite the opposite, actually. My approach will allow me to remove the Yeti power station and return the trailer to identical from-the-factory functionality. If I chose to do this when selling the trailer, my total sunk cost will be about $400 (assuming I stay with only portable solar panels), and I retain the Yeti. If the new owner wants to install a Yeti, they plug it in, turn a few switches, and have the full solar/inverter functionality.

Hi

You should do something to fully disable the existing inverter and the stock converter charger if the Yetti is now the "battery system". Having either of those devices accidentally come on line likely would result in smoke coming out of somewhere .... It needs to be more than just a switch that you "never turn on".

Bob

[wmcneil]

Originally Posted by uncle_bob

Hi

You should do something to fully disable the existing inverter and the stock converter charger if the Yetti is now the "battery system". Having either of those devices accidentally come on line likely would result in smoke coming out of somewhere .... It needs to be more than just a switch that you "never turn on".

Bob

I don't have an existing inverter...I'll be removing the breaker for the converter.

[gypsydad]

Originally Posted by wmcneil

I don't have an existing inverter...I'll be removing the breaker for the converter.

Why don't you have an "inverter"? Did you remove?