I am looking for a circuit that I can use to conserve battery life on my child's battery operated ride on. Some times he will leave the lights and radio on. This ride on is a 24v electronic scooter controller converted ride on(variable throttle). The motors are always hot with key on and the controller pulses the ground when the throttle is pressed.

Is there some sort of voltage comparator/time-delay circuit. When motor voltage drops below 0.5 or lower volts it will disonnect a relay coil after X amount of delay? If you need more info please let me know. Thanks!

 

Seems like you need two separate circuits:

Timer: Shut down the radio/lights/motor-controller a fixed delay time after the toy throttle is pushed...
What would be an appropriate time?

Voltage sensor: Turn everything off when the battery voltage reaches a critical discharged level. SLA Batteries suffer if they are repeatedly discharged below 1.9V/cell (22.8V for a 24V SLA).

 

Does the motor get hot with the key on even if the throttle is not pushed? If so, that would seem to be an error in the design. With the throttle not pushed there should be no power to the motor.

 

No the motors do not get hot. At least that is my understanding of it. If you search ebay it is a YK31C 24v 500w controller. Pretty sure it switches ground.

The controller has a low voltage cutout. I just don't want it to get that low to the cutoff point. Just preventative for longer ride time. So, we just need to time out the +12v to the lighting circuit. I would say if the throttle hasn't been used in say three minutes. My thoughts were measuing voltage at the motors to determine the cutoff if there was no voltage there then time delay and off. How would pressing the throttle revive the entire circuit though?

I am open to ideas though that's why I came here!

 

Is the relay coil 12 or 24V?
How much current does it take to operate the relay coil?
What kind of switch starts the timer? can it be a momentary push button?
If it is a key-switch (or toggle switch), then what resets the timer for a new cycle?