Is 12 mph too fast for a 3-year-old?

Yes, for most 3-year-olds. The age floor is 3, but 12 mph is near the top of the ride-on class, so plan on close supervision and open, car-free ground. Younger or timid riders are better served by a slower 6 V or 12 V bike.

How does it compare with a 12 V kids' dirt bike?

It has roughly double the voltage and a 350 W motor, so expect more torque on grass and small inclines and a higher top speed. A 12 V bike is lighter, slower and usually simpler for beginners.

How long does the battery last on a charge?

The maker does not publish a runtime or charge time for this model. Expect a typical 24 V ride-on session of roughly 30 to 60 minutes, and charge fully before each use.

What age and size of child does it suit?

It is aimed at kids from age 3, but the speed and 24 V power suit older, more confident riders best. Check the seat height and weight limit against your child before buying.

Does it come with a charger and battery?

The listing describes a 24 V battery, and ride-ons in this class normally ship with a charger. Confirm the box contents with the seller before ordering.

Can it handle grass and hills?

The 350 W motor gives it more pull than most 12 V toys, so light grass and gentle slopes should be manageable. Steep or wet terrain will still bog down a kids' ride-on.