Adjustable article of furniture comprising at least one adjustable element and an actuator system (6, 10, 26) for adjusting the adjustable element, where the actuator system comprises: at least one electrically driven linear actuator (6,26), and possibly also a driven drive wheel, an electrical controller with an operation device, connection means for a power supply via mains, a power supply in the form of a battery pack with rechargeable batteries of a first type, characterized in that the actuator system is equipped with a frontend as interface for the battery pack, where the frontend: - enables the battery pack to be equipped with a second type of rechargeable batteries than the first type of rechargeable batteries, which to the actuator system still appears as a battery pack containing the first type of rechargeable batteries, - comprises a charging circuit configured to adapt the charging voltage, i.e. both up and down, with a view to supplying the battery pack with an appropriate voltage for charging the battery pack, - during idle periods, where the current draw is below a given threshold, adapts an output voltage corresponding to the output voltage, which a battery pack of the first type with the same remaining capacity would have, - when a current running out of this exceeds a predetermined threshold, regulates the output voltage, such that the controller is supplied directly with the output voltage of the battery pack. at least one electrically driven linear actuator (6,26), and possibly also a driven drive wheel, an electrical controller with an operation device, connection means for a power supply via mains, a power supply in the form of a battery pack with rechargeable batteries of a first type, characterized in that the actuator system is equipped with a frontend as interface for the battery pack, where the frontend: - enables the battery pack to be equipped with a second type of rechargeable batteries than the first type of rechargeable batteries, which to the actuator system still appears as a battery pack containing the first type of rechargeable batteries, - comprises a charging circuit configured to adapt the charging voltage, i.e. both up and down, with a view to supplying the battery pack with an appropriate voltage for charging the battery pack, - during idle periods, where the current draw is below a given threshold, adapts an output voltage corresponding to the output voltage, which a battery pack of the first type with the same remaining capacity would have, - when a current running out of this exceeds a predetermined threshold, regulates the output voltage, such that the controller is supplied directly with the output voltage of the battery pack. - enables the battery pack to be equipped with a second type of rechargeable batteries than the first type of rechargeable batteries, which to the actuator system still appears as a battery pack containing the first type of rechargeable batteries, - comprises a charging circuit configured to adapt the charging voltage, i.e. both up and down, with a view to supplying the battery pack with an appropriate voltage for charging the battery pack, - during idle periods, where the current draw is below a given threshold, adapts an output voltage corresponding to the output voltage, which a battery pack of the first type with the same remaining capacity would have, - when a current running out of this exceeds a predetermined threshold, regulates the output voltage, such that the controller is supplied directly with the output voltage of the battery pack.