Most charging adapters do not charge at all or only with a fraction of the rated power when the lights are switched at the same time. If a USB device is to be charged, it is recommended that the lights are switched off. With the universal charger "Forumslader V5", an Edelux DC 6 to 75V headlamp can be connected to its 12V output and the lighting and USB devices can still be operated - provided the charge level of the buffer battery is high enough.