question

I don't find a MP II 2000 VA model but there is a Multiplus 2000 (not the Compact) in the same cabinet as the MP IIs.

The manual for the MP || lists wire size for the 3000 VA 12 volt model as 2x 1/0 AWG for up to 5 meters

The manual for the 2000 VA Multiplus (and the Multiplus Compact for that matter) requires one 70 mm2 = 2/0 for up to 5 meters and a 300 amp fuse.

I had similar install issues mounting batteries and Multi Compact under the bathroom sink in my travel trailer. I did manage to get 2/0 wires to where they needed to be. In hind sight, I should have removed the front of the cabinet for easier access. I'd recommend it if you have that option.

2/0 is 70 mm2 and an equivalent would be two #2 AWG (35 mm2) in parallel for each connection. Just keep the paralleled connections the same length if you go that route.

Kevin, YOU are correct! I meant to type in 12/3000!
My error - my excuse I'm coming down with a nasty cold! Sorry for the mistake!

First, No way can I get more access space. I have a small cavity with only 13w X 20h access hole that is in the front of the basecamp UNDER the bottom of the sink and drain pipe with the shower wall on the left, the frig on the entry hole wall and the 3rd wall the curve of the outside wall to the nose of the front trailer wall! LOL

"The manual for the MP-II 12/3000/120-50 lists wire size as 2x 1/0 AWG for up to 5 meters"
Yes, now is that 5-meter limit to be the cumulative distance of each of the positive and negative cables between every one of the 4 100Ah batteries terminals, over to the Lynx, then over to the MP-II terminals? Or just the distance of the longest leg (battery terminals of (+) added to distance over the the Lynx terminal since that is the longest length between any of the components?

So if the + total of battery positive terminals is 6 feet(1.524 meters) to just the Linx (+) terminal for only the (+) cable, AND the same for the negative cable = a total of both positive and negative of 3.5 meters I'm well under the <5 meter value. (Do I add both the positive leg and the negative leg distance of each together OR just the distance of one length of either the + or - cable to define that I am below the <5 meter value?)

Is that logic correct OR do I have to now add the cable from the battery terminals to the lynx to the MP-II and the cable from the Lynx to the frame ground too?

Yes, that is my confusion. I'm not a EE by any stretch of the mind - retired Nerd.
So my thinking is just a simple 30Amp AC system in the little Basecamp should not need 4/0 cable. 2x 2/0 at best for each current. Batteries will be two columns of two high each with EACH battery strapped to the floor with a separator board between each of the two in the stack.

Here is a copy of part of my spreadsheet I built to calculate my Ah's needed:

To add to the "joy" of this project, my lady few Delta from Seattle to RDU two weeks ago. She had a direct flight, sat on the tarmac for 5 hours in the plane, was put back in the terminal till the next day, and flown to ATL to catch another flight to RDU. Talk about a breeding poll to dive into to catch a virus!

We are now fighting a very nasty virus together and I'm way too weak to work on the trailer. Glad I'm retired! As bad as this is, figure I have 4 more days of misery left.

Now I understand and have been told that I only need a 2000 watt inverter, but MPII is not offered as such BUT you can in the setup limit the input load to only 2000 watts! Thus that would disable the other 1000 watts the inverter is capable of producing making the cable load less and a smaller Amp fuse in the + line to the Lynx the better choice over the 400Amp? (https://community.victronenergy.com/questions/85286/does-the-multiplus-3-kva-invertercharger-allow-me.html) You need to scroll down quite a ways to get a clean definition.

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First, I'm confused in more ways than one.
I found a chart that shows for one 1/0 cable rated at 167F takes a 150A fuse and rated at 194F takes a 170A fuse.
But IF I run two 1/0 what would be the proper size fuse?
And if I mate both of the 1/0 cables at and from the Blue Sea + line Fuse block is it the same?

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Just dragged this aching body to the Basecamp 16X, as best as I could. Measured the distances:

Parallel connect each pole of the battery terminals will be 70" for each + & -.
From the last in the chain to the lynx and then to the MPII terminals will be at 116", again for each + & - cable

For only one current, say +, I need 186" of cable = 15.5 feet.

The manual says can run two 1/0 cables up to 5 meters total length, or 32 FEET!

Thus IF what I have said for a single cable is correct of 15.5 feet I am well below the 32-foot limit.
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Here is were I get confused. I read at one DIY site that you must ADD the total length of the + cable to the total feet of the negative cable to use to determine the cable size.

Is that true?

Even if true, I would only be at the upper limit of just 2 x 1/0 cables, and thus for buffer should I to a 2/0 cable of two strands per pole/connection point just for added safety?

Sincerely appreciate any help educating this retired 77-year-old computer Nerd (Cray & SGI Super Computers).

Best,
Jack

I have purchased all of the electronics, batteries, etc and now will install/place the batteries and start linking the electronic components together.
Here is my schematic and I would appreciate your review and offering corrections that you suggest! The 2x2/0 cables are per the factory manual, but all of the other cables as well as fuse sizesare open to review.

JFB 16X Electrical Design.png

PS: In particular, should I run 2 x 2/0 cables to the frame ground or is one more than adequate?