My 40ft 5th wheel 1020 Watt PV Build

[LanduytG]

Been collecting components since April. I have finished building the battery packs 16 280aH Eve cells in 4s4p configuration. Been installing components as time permits. I have just about everything in except the PV system. Below is a list of components I'm using

Victron Multi Plus 12/3000/120-50 inverter
Victron Smart Solar MPPT 150/70 SCC
Victron Smart Battery Protect 12/24-65
Victron BMV 712
Victron Celbro GX for system monitoring
Victron Touch 50 display screen
Victron Orion 12/12-30 DC to DC battery charger
4 Canadian Solar 255 watt panels from SanTan Solar
16 Eve 280aH in 4s4p for 1120 aH of storage

Have been testing the inverter the last couple of days and it works great. Using the A/C as a load and it draws 100 amps and everything is cool as a cucumber. Micro wave draws 138 amps. Using 4/0 cable and all total with battery jumpers etc is only about 4ft total. I onoly see a .2 volt drop when micro wave is running and .1 volt drop with A/C.

I need to finish up some other wiring then on to installing the PV array. Going to pull 6ga from the roof so I can go with all 4 panels in parallel if I so desire. I have the 2 spots where the PV will go picked out. My plan today is to go up today and use a piece of cardboard cut to size and see where everything will lay. Still up in the air on how and what I'm going to use to mount them. The hole to get cables below is going to be close to the black tank vent as that area goes right down to where I need to go.

Some my wonder why I'm using the 65 amp battery protect. That is for the DC panel feed only. The inverter will be set to shut down at 12.1 volts and battery protect at 12 volts. I don't want to use the BMS as the main protection for battery discharge limits.

At first I was not going to spend the money on the Victron components and was going to use Aim's inverter and Epever SSC but decided to go Victron and I'm glad I did. Everything works seamlessly together and I can use my cell phone to setup everything up.

One thing I'm going to change is the BMV712 out to use the Smart Shunt. I had the BMV712 bought before I decided on the Cebro GX. But know big deal I will use it in another project.

Will get pics posted when I'm further along and have all wires tidied up....


Greg

 

[Sojourner1]

It sounds like a great system with quality components with boondocking adventures ahead, full luxury living.

Lithium/ solar is a game changer if you don't want to run a generator. Where I'm boondocking right now in the Black Hills NF for the past 2 weeks I catch shading from pines on 1/2 my array on the roof through out the day. Been bouncing around in a psoc since arriving 90%-30%. Just this morning at a lower SOC and still using high draw items. Now let solar do its thing again.

When I have too much free time on my hands, here are some readings from the past days during this psoc period. It will be like this now off and on with shorter sunny days and the solar arc changing till spring.

Running like a fine tuned swiss watch.

Once you dial in your system and truly trust it it should be a set it and forget life.

Edit: The Magnum inverter is set to 12.0 lvd.

 

[LanduytG]

Still some cleaning up to do and need to wire SSC. But this is and idea of what I'm doing.

Greg

 

[David S]

@LanduytG Is your trailer 30 amp or 50 amp? If 50 amp, how did you choose to deal with the split phase? I keep bouncing back and forth between running 2xMultiplus and using the 3 way switch solution.

 

[LanduytG]

I' using the Smart Phase Control by AM Solar. Works with the multi and feeds both phases. I will get a link up so you can see it. Prissy but cheaper than 2 multi plus. I did a test today and I can run both a/c units at the same time. I do use the micro air easy start on both units. If not for that I couldn't do it. However I'll never run 2 at a time anyway. I just want to be able to run the bedroom unit at night. With 2 running it drew 220 Amos which is close to max power.

Greg

 

[LanduytG]

Here is a link to the youtube video. He also shows how to wire a manual switch to do the same thing. But I like auto because it will not forget to switch. For those of us that might have and occasional senior moment.

RV Inverter Setup! How To Power It All! 50 Amp and 30 Amp. - YouTube

Greg

 

[David S]

Thanks. I'm familiar with the SPC. Last time I looked it was out of stock with no clue when it would be back in. It's fairly pricey too, but I do think it's a cool, no muss/no fuss solution. Thanks for sharing and your build is very cool. I'm getting ready to do my 2007 Jayco Seneca with 280ah LiFePO4 cells, so it's inspiring

 

[LanduytG]

Forgot to add the Smart Phase Selector by AM Solar. This allows you to get full functionality of the electrical system even if you are installing on a 50 amp service. Its nice not to have to be worried what circuits you can and cannot use. All you need to remember is the amount of appliances you turn on so you don't over load the inverter.

Greg

 

[Sojourner1]

If reading the link about the smart link, all it's really doing is eliminating the need for a sub panel and adding a slightly higher idle draw?

If you don't have room for a subpanel certainly can help with designing the system.

 

[Hedges]

Still some cleaning up to do and need to wire SSC. But this is and idea of what I'm doing.

Greg

View attachment 24287

Glad to see cables to the 4P set of batteries are at opposite ends. That approximately matches IR drop and current draw from the batteries (better than having both inverter cables land on the same battery.) But it isn't perfect balance for a system like this with more than 2 batteries in parallel. With two more wires you can make it 100% balanced; every battery sees the load through wires adding up to same current flow and IR drop. Inverter wire carries 100%, one wire carries 50%, one wire carries 25%.

 

[Hedges]

Fuse?
I think I see one near the switch, but not in your equipment list.

Blue Sea has fuse holders and class-T fuses, which can interrupt 20kA from a short circuit.
I don't know the short circuit capability of lithium. My 405 Ah AGM is probably 16kA.
Battery cable resistance will help reduce fault current.

Anybody here know how good lithium battery internal fuses are at interrupting faults from dead shorts?
Of course, you'd rather do that outside the battery and not render it unusable.

 

[LanduytG]

Fuse?
I think I see one near the switch, but not in your equipment list.

Blue Sea has fuse holders and class-T fuses, which can interrupt 20kA from a short circuit.
I don't know the short circuit capability of lithium. My 405 Ah AGM is probably 16kA.
Battery cable resistance will help reduce fault current.

Anybody here know how good lithium battery internal fuses are at interrupting faults from dead shorts?
Of course, you'd rather do that outside the battery and not render it unusable.

Yes their is a 400amp T fuse under the inverter to the top left of the switch.


Greg

 

[LanduytG]

Glad to see cables to the 4P set of batteries are at opposite ends. That approximately matches IR drop and current draw from the batteries (better than having both inverter cables land on the same battery.) But it isn't perfect balance for a system like this with more than 2 batteries in parallel. With two more wires you can make it 100% balanced; every battery sees the load through wires adding up to same current flow and IR drop. Inverter wire carries 100%, one wire carries 50%, one wire carries 25%.

Not concerned with it being prefect. Used all 4/0 and a total of 4ft per side. With a 150amp draw I only see .1 volt drop. When monitoring the batteries via BT the current draw is within about 2 amps of one another.

Greg

 

[LanduytG]

If reading the link about the smart link, all it's really doing is eliminating the need for a sub panel and adding a slightly higher idle draw?

If you don't have room for a subpanel certainly can help with designing the system.

It also allows for both sides of the panel to be feed when on a 20 amp service. Could have done the same thing with a rotary switch but then you have room for error by forgetting to switch it. When spending money on quality components a few hundred more is nothing and makes it the system better.

Greg

 

[Tball]

Still some cleaning up to do and need to wire SSC. But this is and idea of what I'm doing.

Greg

View attachment 24287

Where did you get your battery boxes?

 

[Hedges]

Not concerned with it being prefect. Used all 4/0 and a total of 4ft per side. With a 150amp draw I only see .1 volt drop. When monitoring the batteries via BT the current draw is within about 2 amps of one another.

Greg

It is about battery life. Impact will be less at lower current draw. I don't know the battery characteristics well enough to say if it will make one battery die at 7 years vs. another at 10, just putting on my EE hat and trying to make it nominally a perfect balance. Maybe insignificant, worth less than the cost of two, 15" cables.

I happen to have a single string, 48V, so didn't have to consider the issue.
What I have paralleled are inverters with relays passing through from the grid. I had to balance that to avoid limiting maximum power.

 

[LanduytG]

Where did you get your battery boxes?

Here is my thread about the boxes. Also post 22 show the batteries and BMS inside the box.

Greg

 

[LanduytG]

It is about battery life. Impact will be less at lower current draw. I don't know the battery characteristics well enough to say if it will make one battery die at 7 years vs. another at 10, just putting on my EE hat and trying to make it nominally a perfect balance. Maybe insignificant, worth less than the cost of two, 15" cables.

I happen to have a single string, 48V, so didn't have to consider the issue.
What I have paralleled are inverters with relays passing through from the grid. I had to balance that to avoid limiting maximum power.

I could double up the neg side easy enough but the pos side of the switch is full and don't think I could get another one in there.

Greg

 

[Hedges]

I could double up the neg side easy enough but the pos side of the switch is full and don't think I could get another one in there.

Greg

The idea would like what is shown here:

doubling up on battery bank cables

Recently the forum helped me understand something-you can double up on cables to get better AWG (for example two 2/0 AWG'S act as 4/0 cables between a fuse an an inverter). Is there any problem doing the same on the cables connecting my battery bank? I have 4x100a AGM's connected with 1 AWG...

diysolarforum.com

 

[LanduytG]

Yesterday I put a load on the batteries till they were depleted enough to shut down the inverter. Let me tell you it takes awhile when you have 1120aH of battery. I ran one a/c till it and then the other. Then would run both fans only and it took most of the day. Max draw was 125 amps. I only had .1-.2 volt drop at that load. Amp draw was never more than 2 or 3 amps difference between the 4 batteries. Balance was 4-5 millivolts on 2 for the batteries and the other 2 were running about 20 millivolts.

Today I charged them with the Multiplus at 120amps. Balance was about the same as discharge and amp draw was also about the same. Tomorrow this finish up the SSC wiring and the other than pulling wire from the roof the wiring will be done.

I think I'm really going to like the setup when done. Love all the Victron gear especially the multiplus. Very glad I went that route.

Greg