A battery protection circuit

A power supply arrangement for supplying power from a battery (2) to an electric load (3) comprises a controlled switch (4) having a first state in which a connection is provided from the battery (2) to the load (3), and a second state in which the load (3) is disconnected from the battery (2), and a control circuit (5, 8, 9) for controlling the state of the controlled switch (4). The control circuit (5, 8, 9) is arranged to be disconnected from the battery (2) when the controlled switch (4) is in its second state. By disconnecting not only the electrical load, but also the control circuit from the battery, it is ensured that this circuit cannot draw any leakage current from the battery, when the load is switched off. This means that no over-discharge protection is needed in the battery itself.