Sparks relatively contained inside the drill, are completely normal and occurs when your drill is running at any speed. However, if there are intermittent and violent sparks around the motor, power cord, or battery compartment, this is sign of an issue that must be repaired. Although sparking is part of normal operation, they have the potential to ignite debris in the air such as sawdust. It's even possible to ignite gas, so ensure that your work area is well-ventilated