The replacement itself, minute by minute
Old battery out, the next five minutes are the part cheap jobs skip. The tray gets brushed clear of the white-green corrosion crust, the terminal clamps get a wire-brush clean back to bright metal, and any acid residue is neutralised. Corroded contact surfaces are the number one cause of a car that cranks lazily on a brand-new battery. The new unit goes in, and the hold-down clamp is refitted and torqued so the battery cannot shift; a loose battery in UAE speed-bump traffic hammers its own internal plates apart. Reconnection is the reverse: positive first, negative last, clamps tightened to a firm hand-tight, then a smear of terminal grease or anti-corrosion washers, which matter double in the humid coastal emirates.
The job is not finished at the first start. A conscientious technician verifies charging voltage at the terminals with the engine running, confirms the stop-start system re-arms on cars that have it, performs battery registration where the car requires it, punches the warranty sticker, and takes the old battery away. If the van leaves within ten minutes of arriving, at least three of those steps did not happen.