What is the recommended fast charging rate for a NiCad or Ni-MH battery, in relation to its AHr rating?

The recommended fast charging rate for a NiCad or Ni-MH battery is indeed related to its AHr (amp-hour) rating. The correct charging rate is typically 10% of its AHr rating, commonly referred to as a C/10 rate. This means that if the battery has a capacity of, for example, 1000 mAh (1 AH), the fast charging rate would be 100 mA.

Charging at this rate is advantageous because it ensures the battery is charged efficiently while minimizing the risk of damage that can occur with higher charging rates. Charging at 10% allows for a balance between speed and thermal management, especially critical for nickel-based batteries. These batteries can be sensitive to overcharging and high temperatures, and maintaining a charge at 10% of the AHr helps to prolong their lifespan and performance.

Selecting a faster rate, such as 25%, 50%, or 100% of the AHr, could potentially lead to overheating and reduce the overall cycle life of the battery. This understanding is vital for proper battery maintenance and safety in various applications.