Help understanding these Electrical questions before ordering trailer:

[Damikester892]

Currently ordering a Momentum 25g TT through our local dealer and down to electrical decisions.

Goals:
-Boondock for about a week straight
-Install 400ah Lithium battery bank
-Install larger inverter
-Charge battery bank from generator (Want to see how we make out this way, if its not practical we'll just invest in a larger solar system to keep the batteries charged)
-Not have to re-run too much wiring through the trailer.


Some things I'm trying to understand clearly and some options I'm weighing:

Info: I estimated we'll need about 400ah of lithium batteries which we will be installing upon delivery.
Question: Do I need to change any wiring for this or can I just daisy them together and hook the last end one to the wires that are already coming out the front of the trailer?

Also,

Info: My goal is to have a 2000w or ideally a 3000w inverter on the 25g. However GD only offers 1000w on the TT model.
Question: If I order the 1000w inverter package, will I simply be able to change out the inverter to a larger one or will it require a full re-wire?

Info: If I start off with the 300w solar package, I know that will not be enough to keep the batteries charged.
Question: How long roughly will it take the 4000w generator to charge the 400ah lithium battery bank (assuming we are not running other things like AC while the generator is on)?

Info: The 25g comes with 175w solar and Inverter Prep by standard if you do not choose the 1000w inverter option,
Question: If I just left it on the standard option could I simply just install a 3000w inverter to the inverter "prep" and achieve what I'm trying to do instead of buying the 1000w and tossing it out the window?

Info: From reading on the forums I see the supplied 1000w inverter powers three outlets inside the RV.
Question: If I were to upgrade to a 2000/3000w inverter, how difficult is it to add the other outlets to the inverter (including an exterior outlet?)

[RJAPCOK]

Currently ordering a Momentum 25g TT through our local dealer and down to electrical decisions.

Goals:
-Boondock for about a week straight
-Install 400ah Lithium battery bank
-Install larger inverter
-Charge battery bank from generator (Want to see how we make out this way, if its not practical we'll just invest in a larger solar system to keep the batteries charged)
-Not have to re-run too much wiring through the trailer.


Some things I'm trying to understand clearly and some options I'm weighing:

Info: I estimated we'll need about 400ah of lithium batteries which we will be installing upon delivery.
Question: Do I need to change any wiring for this or can I just daisy them together and hook the last end one to the wires that are already coming out the front of the trailer?

Also,

Info: My goal is to have a 2000w or ideally a 3000w inverter on the 25g. However GD only offers 1000w on the TT model.
Question: If I order the 1000w inverter package, will I simply be able to change out the inverter to a larger one or will it require a full re-wire?

Info: If I start off with the 300w solar package, I know that will not be enough to keep the batteries charged.
Question: How long roughly will it take the 4000w generator to charge the 400ah lithium battery bank (assuming we are not running other things like AC while the generator is on)?

Info: The 25g comes with 175w solar and Inverter Prep by standard if you do not choose the 1000w inverter option,
Question: If I just left it on the standard option could I simply just install a 3000w inverter to the inverter "prep" and achieve what I'm trying to do instead of buying the 1000w and tossing it out the window?

Info: From reading on the forums I see the supplied 1000w inverter powers three outlets inside the RV.
Question: If I were to upgrade to a 2000/3000w inverter, how difficult is it to add the other outlets to the inverter (including an exterior outlet?)

DISCLAIMER: I do not have a solar set up and I don't know much about solar set ups. But I do know something about electricity and maybe I can help you if nobody else chimes in.

Question #1 - I understand you want to connect multiple batteries together to increase capacity (not voltage). To do this, you connect them in parallel, connecting all positive posts together and all negative posts together, and you draw your current from the positive post on one end of the battery bank and the negative post of the opposite end. It should not matter how many batteries are involved as long as they are connected in parallel. As for the wiring, the size of the wire coming off of the battery bank is determined by how much load you intend to draw from the battery bank and not on how many batteries you have.

Question #2 - I do not know what size wire GD uses to feed the 1000w inverter. But here's the catch. 1000 watts at 12 volts is 83 amps. They will most likely use the smallest wire that will carry 83 amps for the given length of the run. If you want to upgrade to a 3000w inverter you will have to supply it with 3 times the current or about 250 amps. That is going to require some pretty heavy gauge wire. One of the keys is the length of the run from the battery bank to the inverter. The shorter it is the smaller the wire can be. On the 120v side of the inverter, the 1000 watt unit will supply 8 amps and a 3000 watt unit will supply 25 amps. It seems doubtful to me that they would use a wire size for 8 amps that would be big enough for 25 amps. But I really don't know that.

Question #3 - This is where you need the solar experts to chime in, because 400ah lithium and 400ah lead acid are not really comparable. But typically, 400ah at 12 volts should deliver about 4800 watts in one hour. The 4000 watt generator should recharge 4800 watts, in a little more than an hour, assuming no other load.

Question #4 - This is too specific to the system for me to answer

Question #5 - I cannot answer this question either.

I hope you find this helpful. Hopefully one of the Solar Gurus will come along shortly and give you better guidance.

Bob

[Scott'n'Wendy]

To take advantage of the lithium batteries a different charger will be required.
You would need to add a main breaker between the four batts and existing wiring. To protect the original wiring.

[Damikester892]

RJAPCOK Thank you for providing your expertise as thorough as you could! My only question to your post is, while I understand the 4000w generator theoretically could recharge 400ah in a little over an hour, I think the charger would limit the charge rate? Curious how much of the generator actually goes toward charging the batteries with nothing else running.

Scott'n'Wendy
I understand the charger needs replacing in order to charge the batteries to higher then 80%-90%.
Do you mean a main breaker between the inverter and the existing wiring? I don't quite understand putting a breaker between the batteries and original wiring.


Thank you both for chiming in!

[RJAPCOK]

RJAPCOK Thank you for providing your expertise as thorough as you could! My only question to your post is, while I understand the 4000w generator theoretically could recharge 400ah in a little over an hour, I think the charger would limit the charge rate? Curious how much of the generator actually goes toward charging the batteries with nothing else running.


Thank you both for chiming in!

Yes... the charger will likely limit the charge rate. But I don't think you can estimate how much because there are too many unknowns. (at least for me. LOL!)

Bob

[howson]

Currently ordering a Momentum 25g TT through our local dealer and down to electrical decisions.

Goals:
-Boondock for about a week straight
-Install 400ah Lithium battery bank
-Install larger inverter
-Charge battery bank from generator (Want to see how we make out this way, if its not practical we'll just invest in a larger solar system to keep the batteries charged)
-Not have to re-run too much wiring through the trailer.


Some things I'm trying to understand clearly and some options I'm weighing:

Info: I estimated we'll need about 400ah of lithium batteries which we will be installing upon delivery.
Question: Do I need to change any wiring for this or can I just daisy them together and hook the last end one to the wires that are already coming out the front of the trailer?

Also,

Info: My goal is to have a 2000w or ideally a 3000w inverter on the 25g. However GD only offers 1000w on the TT model.
Question: If I order the 1000w inverter package, will I simply be able to change out the inverter to a larger one or will it require a full re-wire?

Info: If I start off with the 300w solar package, I know that will not be enough to keep the batteries charged.
Question: How long roughly will it take the 4000w generator to charge the 400ah lithium battery bank (assuming we are not running other things like AC while the generator is on)?

Info: The 25g comes with 175w solar and Inverter Prep by standard if you do not choose the 1000w inverter option,
Question: If I just left it on the standard option could I simply just install a 3000w inverter to the inverter "prep" and achieve what I'm trying to do instead of buying the 1000w and tossing it out the window?

Info: From reading on the forums I see the supplied 1000w inverter powers three outlets inside the RV.
Question: If I were to upgrade to a 2000/3000w inverter, how difficult is it to add the other outlets to the inverter (including an exterior outlet?)

I'd urge you to spend $13 and get Will Prowse's book before ordering your trailer. Work your way through each chapter until there's complete understanding. (It's what I did.)

https://www.amazon.com/Mobile-Solar-.../dp/1546567119





My setup is very close to what you're contemplating. A lot of the upgrades I've done are listed in this thread: https://gdrvowners.com/forum/operati...lts-f-350-mods

You'll also find a lot of threads referenced in the Modifications spreadsheet. https://gdrvowners.com/modifications

Finally, there are "101" type presentations in the Reference Material section of the Solar channel. Look for TucsonJim 's Solar 101 and Battery 101 presentations.

There's a lot to your questions...I urge you to make sure you fully understand before diving in. Very easy to make expensive mistakes. Unfortunately there's no shortcut to full understanding other than doing your "homework" (lol).

Good luck!

Howard

[acoleman43]

Currently ordering a Momentum 25g TT through our local dealer and down to electrical decisions.

Goals:
-Boondock for about a week straight
-Install 400ah Lithium battery bank
-Install larger inverter
-Charge battery bank from generator (Want to see how we make out this way, if its not practical we'll just invest in a larger solar system to keep the batteries charged)
-Not have to re-run too much wiring through the trailer.


Some things I'm trying to understand clearly and some options I'm weighing:

Info: I estimated we'll need about 400ah of lithium batteries which we will be installing upon delivery.
Question: Do I need to change any wiring for this or can I just daisy them together and hook the last end one to the wires that are already coming out the front of the trailer?

Also,

Info: My goal is to have a 2000w or ideally a 3000w inverter on the 25g. However GD only offers 1000w on the TT model.
Question: If I order the 1000w inverter package, will I simply be able to change out the inverter to a larger one or will it require a full re-wire?

Info: If I start off with the 300w solar package, I know that will not be enough to keep the batteries charged.
Question: How long roughly will it take the 4000w generator to charge the 400ah lithium battery bank (assuming we are not running other things like AC while the generator is on)?

Info: The 25g comes with 175w solar and Inverter Prep by standard if you do not choose the 1000w inverter option,
Question: If I just left it on the standard option could I simply just install a 3000w inverter to the inverter "prep" and achieve what I'm trying to do instead of buying the 1000w and tossing it out the window?

Info: From reading on the forums I see the supplied 1000w inverter powers three outlets inside the RV.
Question: If I were to upgrade to a 2000/3000w inverter, how difficult is it to add the other outlets to the inverter (including an exterior outlet?)

Some of this has already been mentioned.

First question: Did you do a power audit to determine your battery needs? Wiring will be based on max possibly energy output. You will need to determine the battery max output, and inverter max throughput, and length of wire. That will help determine your required wiring size.

Second question: If you get a 2000W or 300W inverter, plan on either some minor rewiring or complete rewire to AC main panel and subpanel. If you go 3000W, you should pawer entire RV with inverter which means rewiring to eliminate the subpanel. If you o 200W you will probably want to move lines from the AC main panel to the AC subpanel.

Third question: The charge rate depends on the charger. In other words it will depend on which charger you have to charge the batteries. I don't think the factory charger is setup for lithium batteries so you would have to disconnect the factory charger add a charger that can charge lithium batteries. The specs of the new charger should tell you how quickly you can charge a battery. Also, the battery manufacturers provide optimal charging rate for the batteries. I would follow those rates.

Fourth question: It's probably not that simple. It really depends on what kind of setup you want.

Fifth question: The 1000W inverter powers a subpanel. All you would do is move the desired connections from the main panel to the subpanel. For example, if you want the microwave powered by the inverter, you would move the microwave connection from the main panel and add an additional breaker in the subpanel for the microwave wiring.

As far as wiring in the 25G, both AC and DC panels are up front in the mater bed against the front wall. The batteries are just a few feet away. The location of the inverter/solar charge controller/transfer switch is under the master closet about 3 feet away from the AC and DC panel. They are all next to each other making wiring runs short and avoiding running wires throughout the trailer. But it still takes time, money and lots of planning

As far as the breaker between the batteries and wiring, you would want a main fuse/breaker/battery disconnect as close to the batteries as possible. Size of fuse/breaker is determined by power output through the main 12v wire from the batteries.

[Scott'n'Wendy]

While you are adding four batts for power longevity, they will have the ability to supply a lot more current than the single original in the event of a fault. So to prevent them from melting down your trailer's wiring, the breaker I suggested would limit that ability.
The breaker would be directly after the batts, prior to connection to converter etc..

[Jlawles2]

Something not mentioned often when doing large multi battery in parallel setups is balance wiring. I.E. with 4 batteries if yo connect all of the + and all of the - then draw off of one end, it is possible that the battery closest to the unit feed ines experiences the most draw and the others balance into it. This leads to the 1 battery having issues.

I'm no expert on balancing, but from what I understand, banking the batteries as 1-2, and 3-4, then drawing off of each of these banks together results in better battery life.

Someone with much more battery knowledge than me will most likely chime in and provide a link to a much better explanation.

[ncitro]

Damikester892 You have gotten some great advice here so far, and your system sounds similar to what I am running. I would say you are looking at a pretty major rewire as suggested above.

I wanted to comment specifically on the generator question, you may not realize this but the generator does not charge the batteries directly. It only provides 120VAC, so it simply powers your charger same as if you were on shore power. If you install a larger charger it will charge the batteries faster. My Multiplus charges at 125 amps, and I have a backup 100 amp converter so theoretically I could charge my 600 ah bank from empty to full in about 2.5 hours (600/225). Since lithiums take max charge pretty much until they are at 99% or so this math is pretty easy. In your case with the factory converter I would guess about 40 amps, so from dead you are looking about ten hours of generator time.

[Damikester892]

acoleman43 Scott'n'Wendy Jlawles2 ncitro

You all are very helpful and I appreciate it very much.

I decided to order with the 1000w inverter package with the plan of:

-Installing 4x 100ah Lithium batteries
-Upgrading wire gauge from battery
-Installing fuse/breaker and a battery cut off on the line coming from batteries
-Swapping out inverter to a 2000w
-Upgrading wire gauge going from inverter to subpanel
-Upgrading Converter to a lithium compatible model
-Upgrading wire gauge from converter to batteries.

I still have to determine wire gauge based on draw but atleast I have an idea of what needs to be done.


What I'm expecting this to do is allow me to charge a little bit off of the small 300w solar panel from factory, and if I go with a 125amp converter model I should be able to run the generator for a couple hours every now and then to keep the batteries charged up.
If I missed anything that foils this plan please feel free to chime in.
Thank you all again for the HUGE help 👍

[ncitro]

acoleman43 Scott'n'Wendy Jlawles2 ncitro

You all are very helpful and I appreciate it very much.

I decided to order with the 1000w inverter package with the plan of:

-Installing 4x 100ah Lithium batteries
-Upgrading wire gauge from battery
-Installing fuse/breaker and a battery cut off on the line coming from batteries
-Swapping out inverter to a 2000w
-Upgrading wire gauge going from inverter to subpanel
-Upgrading Converter to a lithium compatible model
-Upgrading wire gauge from converter to batteries.

I still have to determine wire gauge based on draw but atleast I have an idea of what needs to be done.

If I missed anything please feel free to chime in.
Thank you all again for the HUGE help 👍

Sounds like a great plan, you may not need a new converter depending on what you do for an inverter. Off you get an inverter/ charger (such as a Magnum or Victron) they'll work fine as your converter. This is how I run mine most of the time and only have my 100A lithium converter as a backup.

[Damikester892]

Sounds like a great plan, you may not need a new converter depending on what you do for an inverter. Off you get an inverter/ charger (such as a Magnum or Victron) they'll work fine as your converter. This is how I run mine most of the time and only have my 100A lithium converter as a backup.

Oh man I had not looked into inverter / charger combo units.
Is it the steps the same that I listed minus the converter swap?

Also would I just install the combo unit and leave the original converter connected to the main panel so it only comes on when hooked to generator/shore power or would you turn the breaker off for the Converter and only have it as a true backup incase of inverter failure?

[Jlawles2]

Damikester892 the factory on board converter would be unplugged or disconnected (depends on install type) to prevent the new combo unit from fighting it. A properly installed combo unit will auto switch from shore power / charger to inverter mode automatically.

[ncitro]

Oh man I had not looked into inverter / charger combo units.
Is it the steps the same that I listed minus the converter swap?

Also would I just install the combo unit and leave the original converter connected to the main panel so it only comes on when hooked to generator/shore power or would you turn the breaker off for the Converter and only have it as a true backup incase of inverter failure?

Joseph is right, I keep my factory one turned off (I just lol the breaker) so I have it there if I ever need it.

Combo units use the same wiring for the inverter and charger, just in reverse, so it eases your wiring a bit, but does add some cost. The nice thing is the chargers are usually programmable, allowing you to tweak the profile to match your battery chemistry (lead acid vs lithium for instance), and they tend to be very high output (the Victron I have is 125 amps, higher than any converter I could find).