32 Cells - 6 Panels - 2 BMS - 2 SCC - and 1 Inverter

[Boondock Saint]

Long ago in a state far far away . . . I planned on having 2 SCC due to buying different sized panels. Those SCC would both supply a common bank.

Now, with 32 cells on the horizon (well actually slap-assed opposite the earth) I am reconsidering the permanent location of them and dividing the 2 x 48v banks, each located on either side of the RV from each other. The entire banks would be paralleled, not the cells of the banks. So I'm looking at about 12' min of cable between the locations.

Each bank could have it's own BMS and SCC and ideally I could get 6 of the same exact panels on the roof - 3 per SCC.

Then the two 48v banks would be cabled to a common inverter. A BIG manly inverter. The Binford I-5000 . . .

This is quite literally - load balanced and the weight better distributed in my available spaces without major fabrication work.

Of course there are still a lot of what-if's and could be's, but on the face of it, do you seen any reason this is a bad idea, doesn't work, or proof that my public education just really wasn't what I thought it was?

What say ye?

 

[snoobler]

12' of 4/00 should be fine... spendy but fine.

I would treat them as if they were next to each other in every other way.

SCC1 attached to both batteries "diagonally", i.e., (-) on shunt and (+) to (+) on other 16S battery.
SCC2 wired as SCC1
Inverter wired as SCC1

 

[Boondock Saint]

THANKS for that! Interesting idea. I was anticipating running both outputs on 2/00 to the posts on the inverter which would be in the middle distance wise, under the bed where the rest of the electrical dist is located. *gears turning*

 

[snoobler]

2/00 might be fine. Just check your voltage drop. You want essentially none over your interconnects, but sometimes, you don't have a choice.

 

[Boondock Saint]

By having a 48v rail made of 16x280ah cell . . the online calculator says I should have 13,400 Wh or 34.4 kwh.

A l r i g h t y then.

If I wire two of these in parallel with just two positives/negatives together or in the diag construction affore mentioned, how does this change my available wh/kwh? Do I multiple by 2? Are they different depending on the parallel schema?

 

[snoobler]

16 * 3.2 * 280Ah = 14,336Wh

Two of them would be 28,672Wh

Each would have its own BMS

You should only parallel them at the main terminals.

You should connect loads and sources "diagonally" across the bank as mentioned above.

 

[Boondock Saint]

OH . . well now that you out it that way, makes more sense :D

Danka

 

[snoobler]

Bitte

In 1000 words:




Interconnects as shown.

Circled terminals are where all loads/sources are connected.

 

[Boondock Saint]

Dang you beat me to it, Hoowah! But ya, I knew what you meant, I've seen this illustration posed before, just smaller using 4 battle born etc.

I have Will's recommendation page bookmarked too.

With your diagram, I was planning on 2/0 for the interconnect in red, and your suggestion of 4/0 from those posts to the inverter(s).

Since the invert will be in-house, the heavier cable lengths will be less, but not exactly the same length. But probably not enough to make any difference.

 

[snoobler]

The interconnect length must be the same.

The inverter lengths can be different.

5000W inverter? So typical max will only be 5000/48 = 104.2 = 52.1A each battery?

2/0 @ 52A & 48V is only 0.2% over 12'

I'd say you only need 2/0 everywhere. You might see a 0.8% total voltage drop between interconnects and inverter cables.

 

[Boondock Saint]

Yup agreed, Sounds right to me. I dunno about a single 5kw inverter, but I want one or two that can handle bizniz when I gots bidniz to handle.

Your Victron components look awesome. I need a sugar mamma.

 

[Boondock Saint]

Monitoring.

Whatever SCC or inverter I get, I want active monitoring via PC or phone etc. From either and preferably both.

I'm looking at the Victron offerings for BT, WiFi, and the touchscreen panel. Same with MorningStar. I haven't really explored all the offerings from MPP etc yet.



Inverting.

Under the bed of this RV I can remove the existing inverter and transfer switch to make room for a new larger 48v inverter. This would be in close proximity to the breaker panel.

Or I can buy the Victron units that already supply the 120vac and just pull the 120v runs in under the bed and tie into the breaker panel for distro.

If I do that, does anyone already know that the Victron units will sync and supply both outputs exactly in phase? Will I be able to combine those outputs in a single rail or would they need to stay separate? ( I know . . ASK VICTRON and I will if someone here doesn't exactly know ) I was perusing the product literatures last night and watch a couple of videos, just didn't see exactly how the folks who have 2 units have them implemented.

 

[snoobler]

Monitoring.

Whatever SCC or inverter I get, I want active monitoring via PC or phone etc. From either and preferably both.

I'm looking at the Victron offerings for BT, WiFi, and the touchscreen panel. Same with MorningStar. I haven't really explored all the offerings from MPP etc yet.



Inverting.

Under the bed of this RV I can remove the existing inverter and transfer switch to make room for a new larger 48v inverter. This would be in close proximity to the breaker panel.

Or I can buy the Victron units that already supply the 120vac and just pull the 120v runs in under the bed and tie into the breaker panel for distro.

If I do that, does anyone already know that the Victron units will sync and supply both outputs exactly in phase? Will I be able to combine those outputs in a single rail or would they need to stay separate? ( I know . . ASK VICTRON and I will if someone here doesn't exactly know ) I was perusing the product literatures last night and watch a couple of videos, just didn't see exactly how the folks who have 2 units have them implemented.

If you have a 50A RV system, you have a conundrum unless you never connect to shore power.

You have to allow for means of different inputs - 30A @ 120V single phase or 50A @ 120/240VAC split phase. You'll need transfer switches to handle that.

The folks that have two have them operating in parallel 120/240VAC split phase. Unit 1 supplies L1/N and unit two is 180° out of phase providing L2. That simplifies things greatly as plugging in 50A just feeds L1/N to the first unit and L2/N to the second unit, so all is well - full POWA. On 30A power, the first unit only gets L1 and N, the second unit gets nothing. This allows the charger on the first unit to charge/float the batteries while the inverter's split phase system works normally. As long as you don't exceed the 30A input for extended periods, you should end the shore plug-in period fully charged.

 

[Boondock Saint]

Thanks for the exacting reply. I didn't mean to infer that I wouldn't need any transfer switch at all, just that I can scooch mine over a tad for space - OR that some AIO type units have the xfer switch built in. But since I did mention Victron, maybe the multi or multi II the answer was most informative.

As long as you don't exceed the 30A input for extended periods, you should end the shore plug-in period fully charged.

I don't want this restriction. From a technical point and expense it isn't much to upgrade an RV to 50A.

I'm not in favor of one unit doing all the heavy lifting while the other unit floats along. Pfft freeloaders.

I want the ability to do 30A or 50A when possible. I have no intentions of adding 240v appliances on-board while I own this, but I like the diversity of charging and resell value of the 50A option.

 

[Boondock Saint]

Also just so you don't have to keep saying:
Master AC-out is L1 and N
Slave AC-out is L2 and N

If I want to stick to a 30A services and use 2 Victron's - one for each 48v battery bank, both used to either 1) supply 48v to a common inverter OR 2) supply 12vac to a common rail that I tie into the breaker panel for distribution - then I don't need the Multi-Plus II, I just need the Multi-plus models for 120v?

Can you confirm or provide the model numbers given your understanding of their product line and what I want to do?

I've watched so many Victron videos today I'm starting to think with an accent.

AND if Victron isn't a recommendation, what else do you think fits the bill?

Thx again and thx in advance.

 

[curiouscarbon]

dude johan is sooo helpful

 

[Boondock Saint]

It looks like the best I can do is only qty =5 of the 410w Trina panels. Dimensions LxWxH (79.69 × 39.53 × 1.38 in)

Trina 410W Solar Panel 144 cell TSM-410-DE15H(II)
$1,110.40

Other than it being FIVE PANELS - Anyone have any problems with this product or purchase from A1 Solar Store?

 

[Boondock Saint]

Nothing? No one? chirp chirp

Bueller .. Bueller .. Bueller ..

Anyone doesn't have me on ignore?

 

[curiouscarbon]

present!

yo yo i don’t have useful input at this time but i do hope you

 

[Boondock Saint]

ohhhKaaaay . . this afternoon while siting in the dark singing "All By Myself" with low enthusiasm, I crafted this mock-up of products that can get the job done. This is what I had in my head last year, so not engraved in stone or even the best, just "doable", like the girl that no one really dated in HS.

So where are all the heavy hitters when I need them?