Abstract: A mobile device for measuring at least one electrical biosignal. The device comprises a first input and a second input, a measuring circuit part for providing an output signal indicating the electrical biosignal to be measured, the measuring circuit part comprising a first input and a second input, and a charging circuit part for charging a rechargeable battery inserted in the device, the charging circuit part comprising a first input and a second input. The first input of the measuring circuit part and the first input of the charging circuit part are connected to the first input of the mobile device and the second input of the measuring circuit part and the second input of the charging circuit part are connected to the second input of the mobile device.