The dry cell is the most common type of battery. Dry cells are composed of a metal or graphite electrode and an electrolyte paste. The power output of a dry cell is about 1.5 volts. There are several types of dry cell batteries, such as the alkaline battery, the silver battery and the mercury cell. Once the energy stored in ordinary batteries is depleted it cannot be replenished by recharging.
A rechargeable battery is often referred to as a storage battery. It is technically an assembly of electrochemical cells. Rechargeable batteries are employed in light vehicles, such as golf carts, and as uninterrupted power supplies (UPS) for computers. Once the chemical energy in the cell is depleted, it is recharged using electricity. Examples of rechargeable batteries include nickel-hydrogen and lithium batteries.
Dry cells are generally cheaper than their counterparts, the rechargeable batteries. The enclosed chemicals in dry cells make them safe to handle. However, because dry cells are not rechargeable, you have to dispose of them once their energy is depleted. Replacing the worn out batteries is expensive, and eventually the replacement costs will outweigh the initial savings.
The greatest advantage of rechargeable batteries is that you can reuse them many times. Unlike disposable batteries, their energy can be replenished. Recharging reduces the cost of replacing batteries, but although rechargeable batteries are a good value over their useful life, their initial cost is higher than that of disposable batteries. The major disadvantage of rechargeable batteries is the hazard they pose to the environment. Some rechargeable batteries, such as nickel-cadmium, contain hazardous chemicals.