A therapeutic nsPEF pulse generator system (100, 2150), comprising: an electrode; a pulse generator circuit electrically connected to the electrode and configured to deliver pulses to the electrode; and a controller connected to the pulse generator circuit and configured to determine a voltage level of the pulses delivered to the electrode, wherein the controller is further configured to: cause the pulse generator circuit to be charged to a first charge voltage, cause the pulse generator circuit to deliver a first voltage pulse to a load at the first charge voltage, cause the pulse generator to be discharged to a second charge voltage lower than the first charge voltage using a discharge circuit, cause the pulse generator to deliver a second voltage pulse to the load through the electrode at the second charge voltage, receive a signal indicating an impedance of the load, compare the impedance with an expected impedance, and at least partly in response to the comparison, determine 1) to deliver a third voltage pulse to the load, based at least in part on a determination that the pulse generator circuit passed a test based at least in part on the impedance being within a threshold range of the expected impedance; and 2) to not deliver a third voltage pulse to the load based at least in part on a determination that the impedance being outside the threshold range of the expected impedance, wherein at least one of the first and the second voltage pulses is therapeutic to the load. an electrode; a pulse generator circuit electrically connected to the electrode and configured to deliver pulses to the electrode; and a controller connected to the pulse generator circuit and configured to determine a voltage level of the pulses delivered to the electrode, wherein the controller is further configured to: cause the pulse generator circuit to be charged to a first charge voltage, cause the pulse generator circuit to deliver a first voltage pulse to a load at the first charge voltage, cause the pulse generator to be discharged to a second charge voltage lower than the first charge voltage using a discharge circuit, cause the pulse generator to deliver a second voltage pulse to the load through the electrode at the second charge voltage, receive a signal indicating an impedance of the load, compare the impedance with an expected impedance, and at least partly in response to the comparison, determine 1) to deliver a third voltage pulse to the load, based at least in part on a determination that the pulse generator circuit passed a test based at least in part on the impedance being within a threshold range of the expected impedance; and 2) to not deliver a third voltage pulse to the load based at least in part on a determination that the impedance being outside the threshold range of the expected impedance, cause the pulse generator circuit to be charged to a first charge voltage, cause the pulse generator circuit to deliver a first voltage pulse to a load at the first charge voltage, cause the pulse generator to be discharged to a second charge voltage lower than the first charge voltage using a discharge circuit, cause the pulse generator to deliver a second voltage pulse to the load through the electrode at the second charge voltage, receive a signal indicating an impedance of the load, compare the impedance with an expected impedance, and at least partly in response to the comparison, determine 1) to deliver a third voltage pulse to the load, based at least in part on a determination that the pulse generator circuit passed a test based at least in part on the impedance being within a threshold range of the expected impedance; and 2) to not deliver a third voltage pulse to the load based at least in part on a determination that the impedance being outside the threshold range of the expected impedance, 1) to deliver a third voltage pulse to the load, based at least in part on a determination that the pulse generator circuit passed a test based at least in part on the impedance being within a threshold range of the expected impedance; and 2) to not deliver a third voltage pulse to the load based at least in part on a determination that the impedance being outside the threshold range of the expected impedance, wherein at least one of the first and the second voltage pulses is therapeutic to the load.