CDR stands for Continuous Discharge Rating, which is the maximum current (measured in Amperes or Amps/A) that a rechargeable battery can safely deliver continuously without overheating or damaging the cell.

• Continuous Discharge Rating (CDR): The safe amp limit for sustained, ongoing power draw. For example, a battery with a 20A CDR can continuously supply up to 20 amps safely. Exceeding this rating causes excessive heat and risks thermal runaway.

• Capacity (mAh) vs. CDR: Capacity (such as 3000mAh) tells you how long a battery will last on a single charge (the size of the fuel tank), whereas CDR tells you how fast you can draw power out of it safely (the size of the fuel pipe). High-capacity cells often have lower CDRs, and vice versa.

• Pulse Discharge Ratings: Many manufacturers advertise high "pulse" or "burst" current ratings (e.g., 40A–50A) for short bursts of a few seconds. These are often misleading and should be ignored for high-drain devices that pull power continuously.

• Voltage Sag: If you pull too much current relative to a battery’s internal resistance, the output voltage drops sharply. This can cause your device to shut down or cut out even if the battery still has remaining charge.

• Safety: Using a battery with a CDR lower than what your device demands can cause dangerous overheating, venting, or a failure known as thermal runaway.

• Common Applications:

  • Low-Drain Devices (LED flashlights, small remotes): Require a low CDR (5A–10A).

  • High-Drain Devices (Vape mods, power tools, RC cars/drones): Require a high CDR (typically 20A to 35A+ per cell, or parallel cell configurations like 18650 Battery or 21700 Battery to split the load).