fig5 in other embodiments some level of field weakening current injection may be performed to compensate for variations in machine voltage due to temperature or material variation field weakening may be used in conjunction with load based speed scheduling to ensure that a commanded speed is achieved however if the motor direct current in field weakening mode is above the threshold then the speed reduction method of fig5 may be employed as described above thus the elevator speed control in field weakening mode may augment the speed control based on car load fig8 is a flowchart of a process performed by controller 50 in an exemplary embodiment it is understood that the order of steps in fig8 is exemplary and more than one control block may implemented simultaneously as part of a continuous control process at 300 controller 50 determines if battery 18 is overloaded in motoring mode by monitoring battery voltage sensed at voltage sensor 51 if the sensed battery voltage is too low flow proceeds to 302 where controller 50 reduces the car speed by an amount e g a set m sec or a percentage of current speed flow proceeds back to 300 where the controller 50 continues to monitor battery voltage until the battery voltage is at a suitable level further speed reductions at 302 may be employed in a stepwise manner until the battery voltage is below the threshold if battery 18 is not overloaded at 300 flow proceeds to 304 where controller 50 determines if battery 18 is overcharged in regenerative mode by monitoring battery voltage sensed at voltage sensor 51 if the sensed battery voltage.