Being independent can be incredibly fulfilling.
It can also be fucking exhausting sometimes.
My car battery died, so I ordered a new one. I carefully checked the amperage, dimensions, and compatibility with my car model. It arrived, I removed the old battery (which was no small feat, and I was ridiculously proud of myself when I finally managed it) and then discovered that the terminals on the new battery were reversed and it wouldn't work.
So now I have to return it. Which means carrying a 15 kg battery to the post office.
Then I have to wait for the correct one to arrive.
And after that, I get to figure out why two of my tyres are flat (no problem, I have a spare tyre and ordered a charger/air blower thingy, hopefully it will work).
I am perfectly capable of taking care of my own shit.
I'm just getting a little tired of it. But lesson learned: buy the exact same model of whatever you need to replace if you can.
/rant
The cables almost never have any slack, and as OP said, the terminals are offset to an edge of the battery, even sometimes located on the front face of the battery. Car batteries suck.