my black and decker avid power drill smells hot and suddenly turned off

Diagnosis

The sudden shutdown accompanied by a burning smell in the Avid Power 20V drill is the result of the Thermal Overload Protection (TOP) circuit engaging. This is a safety mechanism built into the 20V Lithium-Ion battery pack and the drill's motor controller to prevent a catastrophic failure, such as a melted housing or a battery cell rupture. When the internal temperature of the motor windings or the battery cells exceeds a specific threshold (typically around 60°C to 70°C), the circuit breaks the electrical connection to stop heat generation. The "hot smell" you are experiencing is likely the scent of ozone from the motor brushes or the overheating of the plastic gear housing. This happens when the tool is subjected to "stalling"—where the drill is pressed too hard into a material, slowing the RPMs while the current draw spikes. This creates a massive amount of heat in a very short window. You can confirm this by feeling the vent holes near the rear of the motor; if they are radiating intense heat, the thermal cutout has been triggered.

How to Fix It

Follow these precise steps to reset the tool and ensure no permanent damage has occurred:

1. Immediate Disconnection: Press the battery release latch and slide the 20V battery pack completely out of the tool. Do not leave it attached, as the battery can continue to discharge slightly or maintain heat transfer from the motor.
2. Passive Cooling Phase: Place the drill chassis and the battery pack on a non-flammable, cool surface (like a concrete garage floor or a metal workbench). Do not put the battery in a freezer or refrigerator, as condensation can cause a short circuit in the terminals.
3. Ventilation Clearance: Use a can of compressed air or a soft brush to clear any sawdust or debris from the motor vents. Blocked vents prevent the internal fan from dissipating heat, leading to faster overheating.
4. The 30-Minute Rule: Wait at least 30 minutes. Even if the exterior feels cool, the internal copper windings of the motor take significantly longer to reach a stable temperature.
5. Cold Start Test: Reinsert the battery. Start the drill on the lowest speed setting (Switch 1) for 5 seconds without a load to ensure the motor spins freely and the smell has dissipated.

If That Didn't Work

• Check for Mechanical Binding: If the drill smells hot but won't restart, the chuck may be jammed. Manually rotate the chuck by hand to ensure it isn't seized. If it feels "gritty," a piece of debris may be lodged in the planetary gears, causing the motor to work overtime and trip the sensor immediately.
• Battery Cycle Reset: If the battery won't charge or power the tool after cooling, it may be in a "deep sleep" protection mode. Place the battery on the charger for 10 minutes, then remove it and try to trigger the tool. This can sometimes "wake up" the Battery Management System (BMS).
• Bit Compatibility Check: Ensure you aren't using a dull drill bit. A dull bit creates significantly more friction and requires more torque from the motor to penetrate the material, which causes the motor to overheat even if you aren't pushing hard. Replace the bit with a sharp, cobalt or titanium-coated alternative.
• Inspect for Melted Terminals: Examine the gold-plated contact points on both the battery and inside the drill handle. If you see any blackened or melted plastic, the thermal event caused a physical short, and the tool will require professional repair or replacement.

Heads Up

• Avoid "Squeezing" the Trigger: Do not hold the trigger at 50% power when driving large screws; this increases heat buildup. Either use full power or a steady, controlled burst.
• The "Scent" Warning: If the burning smell persists after the tool has cooled and you restart it, stop immediately. This indicates a permanent failure of the motor brushes or a shorted winding.
• Charging Caution: Never place a hot battery on the charger. Charging a battery that has just tripped its thermal limit can permanently degrade the lithium cells and reduce the overall lifespan of the pack.
• Duty Cycle Management: For beginner projects, remember that these home-DIY drills are not designed for continuous industrial use. Give the tool a 2-minute break every 15 minutes of heavy drilling.