An electronic circuit and method for measuring currents during charging and discharging of a secondary battery are disclosed having a secondary battery, at least one shunt for determining the electrical current during charging and/or discharging of the secondary battery by measuring the voltage drop over the shunt, a switchable electrical load, two connectors for connecting a preferably switchable power supply to the electronic circuit for charging the secondary battery and a voltage measuring device. A first shunt is connected in series between the electrical load and the secondary battery, and a second shunt is connected in series between one of the two connectors for connecting the power supply and the secondary battery, wherein the first shunt and the second shunt are connected to the same one of the two battery terminals of the secondary battery, and in that the voltage measuring device comprises only one voltage tapping connected to the electrical conduit between the first shunt and the switchable electrical load and measuring the electrical potential with respect to ground, as defined by the ground potential of the voltage measuring device.