Hi @Abu N Ansary,
Welcome to the Dyson Community!
The runtime of the Dyson V12 Detect Slim vacuum depends on which power mode you have your machine set to, and which accessory or motorised floor tool you’re currently using. The remaining runtime shown on your machine’s LCD display will update in real time to reflect how you’re currently using the machine. Up to 60 minutes runtime is available if you’re using your machine in Eco mode, and with a non-motorised tool attached.
We recommend using your machine in Auto mode for the best experience. In Auto mode, suction power automatically increases when higher concentrations of dust are detected. Once the dust is removed, power returns to normal to conserve the battery - balancing power and runtime.
Hope this helps!