Check this out for me?

[AA93]

Hello folks
I could use some assistance going over my plans for a 12v DC to 110v AC system for my tool trailer
At this time I do not plan on adding any solar power.


Wiring Diagram:

I currently have 2 batteries. My diagram was very simple.

I am considering adding a 3rd, and it has made it difficult for me to imagine it all being fully balanced, so here is what I came up with.
Each battery will have
-same round trip distance to primary bus bars

Primary and secondary bus bars will be diy from 3/8" x 1" copper bar
Also I am only using high quality copper lugs etc

-2/0 copper wire from each battery to bus bars
-Terminal fuse 200a
-on/off switch

From primary bus bar to secondary bus bar
(+)side (2) 4/0 copper welding wire
(-) side, (2) 4/0 copper welding wire to shunt, to (2) 4/0 copper welding wire to secondary bus bar

**I do not like the idea of connecting two 4/0 wires to shunt directly, and have considered another 3 post bus bar on each side of the shunt

Secondary bus bar (connections same for + and -)
(2) 4/0 copper welding wire to inverter ***Considering additional switch to disconnect inverter ***Also considering fusing this connection

Busbar also connected to 12v fuse box, and charger. Depending on what devices etc I will choose cables and lugs for this later

My questions:

I have a victron 1000A smart shunt.
Is this a good idea for this system?
I like the monitor that comes with some of the others.
(I am aware it needs powered and it isnt in diagram)

Any fusing recommendations? I like the terminal fuses, as space will be limited in the cabinet where this goes

The cabinet: It would look really cool to have all of these components mounted to polycarbonate panels or plexiglass
Can this be done or should it always be avoided?

Recommendations on AC charger? I will plugging into 110v ac outlet mostly at home, but sometimes a customers house. I was thinking if i do get the 3rd battery, I will want a 60a charger. I do not want to totally cheap out on this, but I dont want something too ridiculous either.

Most of this system will be scrapped for parts for a larger trailer in 2027, or for another offgrid project the same year.


All following information is not totally relevant, but gives background and can be skipped right over:

The main purpose of this trailer is to install seamless gutters.

My inverter is a cheap modified sine wave inverter. Capacity is 5000 watts, and 10,000 surge.
***I know, this is ridiculous for a 12v system. Realistically, my maximum use through the inverter at surge will be about 4000 watts.

And you guys will love this, the machine makes gutter very quickly, so it doesnt run for very long. For a very large house, it would only need to run maybe 6 or 7 minutes total.

However, in order to get the correct length out of the machine, it has to start many times. A regular run of gutter requires about 4 starts to fine tune the length. A regular house has 5 or 6 runs, So we are talking about starting(surging) the motor 25 or 30 times. Not in rapid succession though.

So we are surging often, but not actually running anything for much time.

My estimation is that I will be able to do 5 jobs on a charge, I only do 1 a day and in a scenario where I need more power I can always bring a small or large generator or plug into the house I am working on.

Power System Check – Tool Trailer Load Breakdown

Battery System:

• 560Ah total (2x Wattcyle 280Ah LiFePO4 in parallel)
• 12V system
• 5000W cheapo inverter with 85% efficiency

DC LOADS: All wired from fuse box ***About 8 Led bars, 2 larger bars, small strips, phone charger

Total: 30A (Just to be safe)

AC Devices (Powered through inverter):

Gutter Machine

• Starting Amps (AC): 20A
• Running Amps (AC): 10A
• Starting Amps (DC): 216A
• Running Amps (DC): 108A

Miter Saw

• Starting Amps (AC): 27A
• Running Amps (AC): 8A
• Starting Amps (DC): 291A
• Running Amps (DC): 86A

Power Strip

• Running Amps (AC): 10A
• Running Amps (DC): 108A

Compressor

• Starting Amps (AC): 14A
• Running Amps (AC): 8A
• Starting Amps (DC): 151A
• Running Amps (DC): 86A

 

[robbob2112]

You have the right idea with the MRBF on the terminals of each battery. At 12v they have a high enough AIC to do the job. You don't really need the second positive bus bar, just one with enough studs to connect everything on a single would work. You can use it, just not required.

The type switches you picture are not the best of that style -- stick with Blue Sea 6006 series or the 3000HD series of switches. And try to never turn them off when current is flowing.

Shunt size wise --- the larger the shunt the higher the minimum detectable current will be. So a 1000a shunt might not have the resolution to pick up 1amp where a 300amp shunt would. Something to look into and make a decision.

For connecting the lugs to the bus bar - the 1000a shunt has a bolt on top and one that goes through it front to back. So you can connect 3 wires directly to it without stacking the lugs.

But overall looks like a good first design.