Plan for Lithium and Solar upgrade

[TowmaterATX]

Hi all,

I am picking up a 2021 GT 25FBT on Wednesday this week and I'm already plotting what the upgrades will look like. It does not have the factory solar option and I wanted to add Lithium for some more primitive camping. Right now these plans show just 4 x 100W panels on the roof, and I plan to add portables if I find I need more solar.

Victron BMV 712
Victron Multi Control
Victron Multiplus 12/3000
3x Battleborn BB10012
Progressive EMS 50A
Victron MPPT 100/50
Various fuses, breakers, switches, etc.
Manual Transfer switch to let Multiplus power entire trailer

See the attached picture for the wiring diagram. Does anyone see any problems? have any suggestions? I'm all ears.

Also, what is the pre-wire size for the solar on the 2021 GT? Is it 8 or 10 AWG? I see folks on the forum posting both.

I was planning on a Color GX but the Cerbo GX looked interesting and I need more time to investigate. I can always start with this and add the GX later.

Thanks!

[waninae39]

I used all the same parts three years ago
A few suggestions

3 separate disconnects, 1 all solar, 2 front lift connections, 3 isolate battery

I also placed the air con on the multiples AC2 connections, all other ac is on AC1

[GMFL]

You need a disconnect switch between the solar panels and MPPT.
Also use the blue sea 500A switch between the batteries and the inverter ( is ring a 400A fuse on a 400A switch the switch would be the fuse)
I would recommend also using a 400A T-Class fuse and holder as your main verses the ANL pictured.

The pre-Wire will be 8AWG wire.

[TowmaterATX]

Originally Posted by waninae39

I used all the same parts three years ago
A few suggestions

3 separate disconnects, 1 all solar, 2 front lift connections, 3 isolate battery

I also placed the air con on the multiples AC2 connections, all other ac is on AC1

Thanks for the suggestions. What do you mean by front lift connections?

I will add the additional disconnects.

[rowiebowie]

Looks like a nice setup.

[TowmaterATX]

Originally Posted by GMFL

You need a disconnect switch between the solar panels and MPPT.
Also use the blue sea 500A switch between the batteries and the inverter ( is ring a 400A fuse on a 400A switch the switch would be the fuse)
I would recommend also using a 400A T-Class fuse and holder as your main verses the ANL pictured.

The pre-Wire will be 8AWG wire.

Good point on the switch exceeding the fuse capacity.

Yes. I meant to put the disconnect for the solar to controller in there. I'll add it to the diagram and the circuit.

I just looked up the difference in the ANL vs T fuses. Battle born had the ANL when I was ordering I threw it in. I'm going to order the Blue sea T fuses and fuse holder.

Thanks for the feedback.

[ASFC25_2019]

Very nice. I would check out a Magnum hybrid inverter MSH 3012M. This way, shore power, and battery power can be combined and used simultaneously or in combination. See what you think. Good luck

[TowmaterATX]

Originally Posted by ASFC25_2019

Very nice. I would check out a Magnum hybrid inverter MSH 3012M. This way, shore power, and battery power can be combined and used simultaneously or in combination. See what you think. Good luck

From what I understand the Multiplus from Victron does the same. That's why I wired up the manual transfer switch. I can be running off 15A at home and if I need to pull more for a bit, the Multiplus will use the batts to make up the difference.

I also ordered two Micro air easy starts. They are not depicted on the picture. But that should allow me to run both ACs on my 3200W inverting generator with the "hybrid" power from the Victron Multiplus.

[TowmaterATX]

New diagram with the suggested changes.

Thank you all for the feedback and for taking a look. It's going to be a lot of work, but I'm looking forward to it.

[pcskier]

If full parallel, I would pull 6 awg wire from the roof rather than use the 8 awg. at 18v and 20 amps from the four panels, at a 2% loss would require 8 awg to only be ten feet. If you're OK with higher losses (check the calculators) stick with the prewire but I think most people who use the prewire go with series parallel configuration rather than full parallel. It usually winds up to be not very difficult to pull new wire, depending on routing you choose.

[TowmaterATX]

Originally Posted by pcskier

If full parallel, I would pull 6 awg wire from the roof rather than use the 8 awg. at 18v and 20 amps from the four panels, at a 2% loss would require 8 awg to only be ten feet. If you're OK with higher losses (check the calculators) stick with the prewire but I think most people who use the prewire go with series parallel configuration rather than full parallel. It usually winds up to be not very difficult to pull new wire, depending on routing you choose.

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.

[GMFL]

Originally Posted by ASFC25_2019

Very nice. I would check out a Magnum hybrid inverter MSH 3012M. This way, shore power, and battery power can be combined and used simultaneously or in combination. See what you think. Good luck

The MultiPlus does the same thing and does it very well. It’s call Current Limit.
Basically what you do is limit the amount of AC current you allow in the trailer through the inverter. ( example: if you are plugged into a 15A circuit you can limit the current the trailer pulls off that circuit to 14A which will prevent tripping that breaker and any power the trailer needs over you set current limit will be provided by the inverter and batteries).
This is very helpful when using larger loads on low Amp power sources.
Also when you back down or “Limit” the current allowed to come into the trailer the MultiPlus will prioritize the “Load” over charging. This means that as your power demand increases the amp used to charge the batteries will decrease to prevent overloading the circuit you are using weather that’s a 50A, 30A, or 15A.

[TowmaterATX]

Something I'm still working through is what to do with the 12V from the 7-way. I was thinking of adding something like the Victron Orion 12/12-9. Or I guess I could leave it disconnected. But I like the idea of putting a little more juice into the batteries from the TV.

For folks that did something similar, what did you do with the 12V from the 7-way?

Thanks to everyone for the feedback and comments. Always more to learn.

[GMFL]

Using a DC/DC Charger is a nice addition. The 12/12-9 would work if you were going to just use the black (+) 10awg wire from the 7pin.
I used a 50A MasterVolt DC/DC Charger and ran 2AWG wire from the front of the truck to an Anderson Power Pole Plug and then ran 4AWG from another Anderson Plug to the charger inside the Trailer.
The MasterVolt Charger is programmed ( User Defined) to trigger “ON” when the input voltage is 13V for greater than 30Seconds And turn “OFF” when the voltage drops to 12.7V.

[switz]

We put five 100 watt solar panels on our 2014 23D International Serenity roof. Think outside the box and put a panel across as well as parallel to the sides of the trailer. We used the Magnum MSH-3012 along with a 300 amp hour lithium battery. The entire solar system is installed under the side sofa with no loss of the slide out bed or storage capacity. We also retrofitted a front power inlet with auto transfer switch so our propane converted Honda 2000 generator can be “attached” to the frame to preclude walking away and be by the propane outlet by the tanks.

[daleyocum]

I have the Flying Cloud version of your trailer and did roughly the same Victron-centric install. I’ve been delighted with the results. I maxed out the roof at 500w of solar. I started out at 300ah of Battle Born batteries but found that too small for our needs to moved up to 500ah. We’re heavy users of electricity, though, with induction cooktop, espresso maker, hair driers, etc. Ours is a single AC model which we can run for a few hours just on battery if needed.

I wired it so every outlet in the trailer is powered all the time, none of this “Inverter” outlet stuff.

You’ll find you want a Victron controller in the GX family. That makes the solar work much better. Without it the solar controller wakes up in the morning, charges, and then won’t restart for the rest of the day, no matter what happens to the battery level. I have a Venus but any of them will do the job.

I doubt you’ll be able to run both air conditioners at the same time through the Multiplus. I just have a little Honda 2000 and it, along with the Multiplus and Easystart do a fine job at a single AC. I could see, if running both ACs is important, having one leg of the generator just run the second AC and the other got through the Multiplus. I love having a generator small enough to lift, though.

Rumor has it the new ACs on 2021s already come with Dometic version of a Easystart so you won’t have to do anything to them.

My trailer came with only 10ga prewire so I had no choice but to drop my own 6ga down through the bathroom vent pipe chase. With 8ga it would be tempting to just use it.

My trucks (F-150) charging current through the 7pin connector is so small that my DC-DC converter didn’t work well. I wouldn’t bother depending on your tow vehicle. The solar will likely recharge everything while on the road anyway.

[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

[TowmaterATX]

Originally Posted by daleyocum

I have the Flying Cloud version of your trailer and did roughly the same Victron-centric install. I’ve been delighted with the results. I maxed out the roof at 500w of solar. I started out at 300ah of Battle Born batteries but found that too small for our needs to moved up to 5800ah. We’re heavy users of electricity, though, with induction cooktop, espresso maker, hair driers, etc. Ours is a single AC model which we can run for a few hours just on battery if needed.

That's great to hear. Well, except the bit about it being the gateway to more $$ for more batteries. But if I'm honest, I've already taken into account that the mounting of the 3 batteries needs to be done in a way to allow for more.

Originally Posted by daleyocum

I wired it so every outlet in the trailer is powered all the time, none of this “Inverter” outlet stuff.

I plan to do the same.

Originally Posted by daleyocum

You’ll find you want a Victron controller in the GX family. That makes the solar work much better. Without it the solar controller wakes up in the morning, charges, and then won’t restart for the rest of the day, no matter what happens to the battery level. I have a Venus but any of them will do the job.

I'm looking at the Cerbo GX. I'm also a EE with computer programming skills and I'm considering hacking around a bit on the open source code they have out for the Victrons. But I'll likely wait and make sure it all works before I start breaking it with my own code.

Originally Posted by daleyocum

I doubt you’ll be able to run both air conditioners at the same time through the Multiplus. I just have a little Honda 2000 and it, along with the Multiplus and Easystart do a fine job at a single AC. I could see, if running both ACs is important, having one leg of the generator just run the second AC and the other got through the Multiplus. I love having a generator small enough to lift, though.

Rumor has it the new ACs on 2021s already come with Dometic version of a Easystart so you won’t have to do anything to them.

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?

Originally Posted by daleyocum

My trucks (F-150) charging current through the 7pin connector is so small that my DC-DC converter didn’t work well. I wouldn’t bother depending on your tow vehicle. The solar will likely recharge everything while on the road anyway.

I have an F250 and I suspect the same. If there was a low cost solution that would allow it to pull whatever it could from the 7-way I think I'd do it. But I would like something I can adjust the input rate on so I don't blow fuses, etc..

[guskmg]

Obviously, time for installation varies with length and internal configuration. As a guide, my 35 footer took 8 days with 2 men working, or 96 man hours. It was worth every penny. I can't believe how little I use power from a pedestal anymore. If you go compost on the toilet you will really br free of hookups. I bought a propane converted Yamaha 6300 for cloudy days and 2 MicroAir EasyStart A/Cs.
Now thats really independence.
guskmg

[TowmaterATX]

Originally Posted by GMFL

Using a DC/DC Charger is a nice addition. The 12/12-9 would work if you were going to just use the black (+) 10awg wire from the 7pin.
I used a 50A MasterVolt DC/DC Charger and ran 2AWG wire from the front of the truck to an Anderson Power Pole Plug and then ran 4AWG from another Anderson Plug to the charger inside the Trailer.
The MasterVolt Charger is programmed ( User Defined) to trigger “ON” when the input voltage is 13V for greater than 30Seconds And turn “OFF” when the voltage drops to 12.7V.

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.