Adjustable article of furniture comprising at least one adjustable element and furnished with an actuator system comprising at least one electrically driven linear actuator with an electrical motor and an electrical controller with an operation device wherein the system in equipped with a battery pack for operating the system during mobile situations where a mains supply is not readily available. The battery pack is equipped with a frontend which allows for the battery pack to be retrofitted on existing actuator systems without compromising the functionality of the actuator system in connection with charging of the battery. Moreover the frontend is adapted to facilitate continued viewing of remaining power on the battery pack even though the technology of the battery pack is replaced e.g. from lead battery to lithium ion battery.
