Ni-Cd rechargeable battery

Ni-Cd rechargeable battery

The nickel-cadmium or NiCd battery is a rechargeable battery that uses a nickel oxide hydroxide and metallic

cadmium as electrodes. Most of these batteries have the cell potential of about 1.2 volts. Since

NiCd batteries are fairly cheap to produce, they are also relatively inexpensive to buy and are used

for many different types of devices.

Advantages
-Low internal resistance (less than half the equivalent NiMH cells)

-High rate charge and discharge rates possible

-Up to 10C discharge rates for short periods typical

-Flat discharge characteristic (but falls off rapidly at the end of the cycle)

-Tolerates deep discharges - can be deep cycled.

-Wide temperature range (Up to 70°C)

-Typical cycle life is over 500 cycles.

-Charging process is strongly endothermic-the battery cools during charging. This makes it possible to charge very quickly, as the I2R heating and endothermic chemical reaction counteract each other.

-Rapid charge typically 2 hours, but can be as low as 10 to 15 minutes.

-The coulombic efficiency of nickel cadmium is over 80% for a fast charge but can drop to below 50% for slow charging.

-The sealed nickel-cadmium cell can be stored in the charged or discharged state without damage. -I t can be restored for service by recharging several charge/discharge cycles.

-The electrolyte is commonly availalable, low cost potassium hydroxide KOH.

-Available in a large variety of sizes and capacities.

Applications

-Motorized equipment

-Power tools

-Two way radios

-Electric razors

-Commercial and industrial portable products

-Medical instrumentation

-Emergency lighting

-Toys