Drills & drivers

Battery charger gets very hot during charging

Chargers naturally warm up during use, but excessive heat, a burning smell, or heat with the charger idle points to a fault that needs attention.

Difficulty
Easy
Time
10–15 minutes to assess
DIY cost
$25–$60

Symptoms

  • Charger is hot to the touch, more than just warm
  • Burning smell coming from the charger
  • Charger stays hot even after charging finishes
  • Discoloration or melting visible on the charger casing

Likely causes

  • CommonNormal warmth from converting AC power during chargingChargers dissipate some heat as a normal part of their function, especially fast chargers.
  • CommonCharger's cooling vents blocked by dust or placement against a wall/fabricRestricted airflow traps heat that would normally dissipate.
  • PossibleInternal charger component failingAging capacitors or transformers can overheat as they degrade.
  • PossibleCharging in a hot environment or direct sunlightHigh ambient temperature adds to the charger's own heat output.
  • Less commonDamaged power cord or plug causing resistance and heatA frayed or damaged cord can generate heat at the point of damage.

What to do

  1. Place the charger on a hard, open surface away from fabric, walls, or clutter that could block its vents.
  2. Charge in a cooler area out of direct sunlight when possible.
  3. Unplug the charger and let it cool if it feels excessively hot, and inspect the cord and plug for damage or discoloration.
  4. Check that the vents (if any) are free of dust; clean gently with compressed air while unplugged.
  5. If the charger smells burnt, shows melted plastic, or stays hot with nothing plugged in and charging, stop using it entirely.
  6. Replace the charger if overheating is more than mild warmth or happens consistently.

Tools and parts

  • Compressed air
Replacement battery chargerSearch: “cordless drill battery charger replacement”

Safety

Use caution

Unplug and stop using any charger that smells burnt, shows melted or discolored plastic, or stays hot when idle; these are signs of an electrical fault.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.