Explain the differences between a dry cell and an accumulator?

Answer 1

A dry cell is a chemical device that produces electricity by a chemical reaction contained in a sealed container. Its contents are not liquid, hence the name "dry" cell. An example is a common flashlight battery or "D-Cell" or "AA-Cell", etc. Those are examples of a carbon rod enclosed in a zinc case and separated from the case and surrounded by a damp mixture of manganese dioxide powder. It is a "Primary Cell" meaning it cannot be recharged once it is depleted. An accumulator, once known as a condenser, is now known by the name "capacitor". It has no chemistry, at least not to react to form electricity. The simplest types are two metal plates separated by a "dielectric" or "insulator". When one plate is connected to the plus side of a battery or power supply, and the other plate is connected to the negative side of the battery or power supply, the capacitor charges up to whatever the battery voltage is, e.g., 1.5 volts DC. When the battery is removed the capacitor stores that charge and holds it for some time (it eventually leaks off). While the capacitor is charged, i.e., has voltage across its two plates or two terminals, it can act as a source of power, just like a battery. However as soon as some current is withdrawn from the capacitor, its voltage decreases, leading to lower capacity to deliver current until eventually its voltage goes to zero. A battery or dry cell can deliver current at a slowly decreasing voltage for an hour or more, depending on the load it is driving. An accumulator or capacitor might deliver current only for a fraction of a second. It can be discharged very quickly since it doesn't store that much charge to begin with, and has no chemical reaction to continue producing electricity.