A power management system comprising: an energy storage device (106a 106b); and a control system coupled to the energy storage device (106a 106b), wherein the control system is configured to: execute a control routine to determine whether to charge or discharge the energy storage device (106a 106b), including determining a difference between a current state of charge of the energy storage device (106a 106b) and a target state of charge of the energy storage device (106a 106b), receiving an output signal characterizing an output rate of a power generator , and determining to charge or discharge the energy storage device (106a 106b) based on the difference and the output signal; determine that the output signal is outside of a specified range for a specified period of time and modify the target state of charge of the energy storage device (106a 106b) in response to determining that the output signal is outside of the specified range for the specified period of time; wherein for this the control system is constituted to determine that the output signal is below a first threshold and, in response, reduce the target state of charge of the energy storage device (106a 106b); and determine that the output signal is above a second threshold and, in response, increase the target state of charge of the energy storage device (106a 106b). an energy storage device (106a 106b); and a control system coupled to the energy storage device (106a 106b), wherein the control system is configured to: execute a control routine to determine whether to charge or discharge the energy storage device (106a 106b), including determining a difference between a current state of charge of the energy storage device (106a 106b) and a target state of charge of the energy storage device (106a 106b), receiving an output signal characterizing an output rate of a power generator , and determining to charge or discharge the energy storage device (106a 106b) based on the difference and the output signal; determine that the output signal is outside of a specified range for a specified period of time and modify the target state of charge of the energy storage device (106a 106b) in response to determining that the output signal is outside of the specified range for the specified period of time; wherein for this the control system is constituted to determine that the output signal is below a first threshold and, in response, reduce the target state of charge of the energy storage device (106a 106b); and determine that the output signal is above a second threshold and, in response, increase the target state of charge of the energy storage device (106a 106b). execute a control routine to determine whether to charge or discharge the energy storage device (106a 106b), including determining a difference between a current state of charge of the energy storage device (106a 106b) and a target state of charge of the energy storage device (106a 106b), receiving an output signal characterizing an output rate of a power generator , and determining to charge or discharge the energy storage device (106a 106b) based on the difference and the output signal; determine that the output signal is outside of a specified range for a specified period of time and modify the target state of charge of the energy storage device (106a 106b) in response to determining that the output signal is outside of the specified range for the specified period of time; wherein for this the control system is constituted to determine that the output signal is below a first threshold and, in response, reduce the target state of charge of the energy storage device (106a 106b); and determine that the output signal is above a second threshold and, in response, increase the target state of charge of the energy storage device (106a 106b). <EOS>