Sebastian Köln

Pretty much all of them.

TVs, cars, motorcycles, children playing or people talking very loud in front of my door, crying children, people upstairs.
I don't mind vacuums, and power tools if I have hearing protection, or cars if they don't change pitch much.

I have cat ears and hear everything, whether I want or not.

The last thing that really irritated me was two mechanical clocks out of sync with one of them having a strong echo from a wall, resulting in 3 distinct ticks each second. I had to stop the one causing the echo.

We have a submersible electric pump that has a 1" hose attached and it gets dropped in the tank and then spit out a huge amount of water, however the pressure is pretty low.
For firefighting I think you would want more pressure. Maybe something like this one.

I am not sure using a pallet is a good idea, as that concentrates the load on just a few small points where it touches the ground. Placing the container directly on soil/gravel/sand spreads the load evenly.
If you find a dry spot that not loose and fill the container only half way initially and observe if it stays level and adjust the ground if it does settle unevenly, it should eventually stop moving. But depending on your luck that might take a few iterations. If you have a good pump and emptying and filling is not a problem, that might not be an issue.

I was also considering to dig a 30" deep hole to place it in, but that is a lot of digging and then gravity will not empty it fully.

Sand was just the first thing that came to my mind to build a level base for something fragile. A level gravel base without sharp peaks could work too.

My primary concern would be uneven settling of the ground. I don't know how deep a proper foundation needs to be for your soil.
Here, a few cm would be enough if it is elevated a bit and water doesn't pool around it, for some soils in wet climates I would probably first ram a few wooden posts into the earth and then concrete tiles on top of them, because they are more of a sponge than a solid.

If you get any amount of sunlight and UV radiation, consider covering it somehow, or it will get brittle over time.

The plastic looks like it needs supporting on the whole area, not just 4 points.
How about preparing an area with compacted sand and placing it there?

The already mentioned Lenovo T series is pretty nice. And if you don't want to spend $$$, then get a refurbished one that is 2 or 3 years old.
They will come with Windows 10 and do everything you want from them.

Win7 is very dangerous because there are no security updates for it anymore, which means any exploit discovered in the last 2? years will still work and anyone with some basic knowledge can run these…

The copper bold is a nice touch, but I think a steel bolt would suffice. The washer part of the terminals have more than enough surface area to conduct the current up and down the stack.
As to mounting it, if you don't want it floating around, maybe a large patch of double sided tape holding a block of wood that acts as a mounting point for the bold? It could even have space for the bold-head countersunk on the backside.

Yours almost looks professional.
Instead of lengthening the power cables, you could extend the sensing wires. Less expensive and doesn't add (almost any) weight.

I am just using standard solid wiring (probably 12 AWG), which should be fine for the peak load of 27A and which will liquefy at 200A, acting as a fuse.

I would probably not go into that effort of adding a coulomb meter and just use a digital voltmeter that uses very little power, since you already have the same functionality in the BMS.
That way you can still get a rough idea of the state of charge, but it is not quite as complex (and expensive).

Okay, good.

The USB chargers are nice.
I want some on my (2.5KWh) battery bank as well, but it has 16 cells in series and I have yet to find a USB-PD (Power delivery) module that supports voltages of 60V (58V when charging stops).