I have a circuit below, both coils are located very close to each other (wrapped ontop of one another). The DC-DC converter is isolated from the input to the output. The insulation on the coil wires cannot block 4kv, will this damage the battery or apply a large voltage to this circuit or will the isolation provided by the DC-DC converter protect the low voltage side? Could I use a diode string to protect the low voltage side? What can I do to ensure the 4kv doesn't feed back to the low voltage side? The circuit is simplified. Thanks for any advice.