On-gating current from the Kv1.5 cardiac delayed rectifier K⁺ channel expressed in HEK-293 cells was separated into two distinct charge systems, Q₁ and Q₂, obtained from double Boltzmann fits to the charge-voltage relationship. Q₁ and Q₂ had characteristic voltage dependence and sensitivity with half-activation potentials of 29.6 ± 1.6 and 2.19 ± 2.09 mV and effective valences of 1.87 ± 0.15 and 5.53 ± 0.27 e, respectively. The contribution to total gating charge was 0.20 ± 0.04 for Q₁ and 0.80 ± 0.04 (n = 5) for Q₂. At intermediate depolarizations, heteromorphic gating current waveforms resulted from relatively equal contributions from Q₁ and Q₂, but with widely different kinetics. Prepulses to 20 mV moved only Q₁, simplified on-gating currents, and allowed rapid Q₂ movement. Voltage-dependent on-gating current recovery in the presence of 4-aminopyridine (1 mM) suggested a sequentially coupled movement of the two charge systems during channel activation. This allowed the construction of a linear five-state model of Q₁ and Q₂ gating charge movement, which predicted experimental on-gating currents over a wide potential range. Such models are useful in determining state-dependent mechanisms of open and closed channel block of cardiac K⁺ channels.