The pad is the most important part
The rubber pad carries the entire holding force. It wears out due to dust, UV, oil and ageing. A pad that has become hard or cracked can no longer maintain the vacuum.
Clean it after every use with warm water and a little soap. Solvents attack the rubber and shorten its service life.
Pumps and valves
The pump is usually robust, but dust can impair valves and seals. On models with an air filter, tap it out or replace it regularly.
If the vacuum drops quickly, check the pad first, then the connections, then the pump. Often a dirt particle is the cause.
Rechargeable battery
Storage
Store suction lifters without pressure so that the pad is not permanently deformed. Do not hang the device by the handle if this presses the pad.
A case or a box protects against dust and damage. That way the device is ready to use straight away next time.
This guide is editorial and general. For safety questions the manufacturer datasheet applies.