Battery protection circuit

A battery protection circuit having two input nodes and two output nodes, the input nodes being connected to a positive supply line and a negative or ground line respectively to couple the input nodes to a battery, and the two output nodes being connected to a positive side of a load and a negative or ground return side of the load, in which the battery protection circuit includes a solid state switch which is configured such that when the switch is in an open state current cannot flow from the battery through the load, and in which the battery protection circuit further includes:

• a first capacitor connected in series with a diode between the two input nodes of the circuit to smooth out negative transient voltages present at the positive input node of the circuit, the first capacitor comprising a polarised capacitor and the diode being oriented to protect the first capacitor during normal use when a positive voltage is present at the input node that is connected to the positive supply line;
• and
• a second capacitor connected in parallel with the first capacitor and between the two input nodes, wherein the first and second capacitors are connected to the input nodes during the open state and during a closed state of the solid state switch, wherein during the closed state the current flows from the battery through the load.