Lead-acid car battery for UPS?

Question

Do it yourself

I took out a weak 7A battery from the UPS, twisted the wires to the battery control unit from the car at 100A, everything seems to be working, nothing will happen, nothing else needs to be added, I mean, maybe some kind of protective equipment is needed, or something else ?

Answer 1

Once upon a time in the early 90s there were rolling blackouts. I took a 60Ah car battery, it lasted 4 hours without any problems. Nothing was heated, the only thing I had to do was to solder the squeaker so as not to annoy. Today, monitors consume differently than before, but system units are much larger, 100Ah, I think, is enough for 2-3 hours.
My UPS was designed for a load of 400V * a, that is, it had almost a double power reserve, but what about you?

Answer 2

In principle, everyone has already said, I wanted to add that the UPS may not be able to fully charge the battery, since the current may simply not be enough. Side effects: an uncharged battery can fail faster, well, Ah is less there. So after 24 hours of charging, you need to turn off the stand and check the voltage, and then draw a conclusion.