The MT 4000 iQ is a compact display instrument that provides information on the current battery capacity of the on-board battery in Ah and % at the touch of a button. In addition, the battery computer indicates the charge status of the on-board battery via a bar display on the side, and the remaining power indicator shows at a glance how long the consumers can still be operated at the current power consumption. All data is easy to retrieve and the functions are clearly and logically structured. The voltage (V) of the on-board battery and starter battery as well as the currently flowing charge/discharge current can also be read. Time and date can also be displayed. The display is equipped with a backlight and a switching threshold is freely programmable. Thus it is possible to automatically switch on a consumer when a certain capacity is exceeded, which then switches off again when a certain value is fallen below again.