Why is do rechargeable batteries come in 1.2V only? Why not 1.5V? Is there any reason for this?

Question

There are many electronic devices that cannot work with 1.2V and I find it very frustrating.

Answer 1

Even though alkaline batteries are rated at a nominal 1.5 volts, they only deliver 1.5 volts when they are fully charged. Alkaline Batteries will drop more linearly from 1.5V to a typical cut off voltage of 0.7V. In fact, over the course of their discharge, alkaline batteries actually average about 1.2 volts. That’s very close to the 1.2 volts of a Nimh battery. However, since the capacity of Alkaline Batteries is measured until cut-off at 0.7V, high-energy consumption rated appliances that commonly cut off at higher voltage cannot fully utilize the energy stored in Alkaline Batteries. This results in wasted energy. During usage, Nimh Rechargeable Batteries will experience a slight voltage drop at first, then will maintain their voltage between 1.2V to 1.0V. The voltage drop is not obvious until it is almost drained, at which point it drops rapidly. The main difference is that an alkaline battery starts at 1.5 volts and gradually drops to less than 1.0 volts. Nimh batteries stay at about 1.2 volts average for about 80% of their discharge cycle.

Answer 2

An ordinary flashlight battery uses a carbon (graphite) post, an electrolytic paste and a zinc casing. The zinc casing is eaten away by the chemical reaction when electrical current is drawn (and the process is not reversible). Rechargeable batteries use different combinations of materials that produce different electrical 'pressures' voltages (but the process is reversible). A battery (or single cell) is like a water pump and its pressure (voltage) depends on what materials were used to build the pump.

Answer 3

rechargeable batteries can only store and release. The chemical batteries employ a chemical reaction to generate 1.5 volts per cell. Automotive batteries (lead acid) can store and release 2.0 volts per cell. Lithium batteries can store and release 3.7 volts per cell. Some lithium batteries also can generate electricity at similar voltages.

Answer 4

Physics.

Regular cells come in multiples of 1.5 volts because they are carbon-based: The difference in voltage is a result of different chemical processes that takes place within the battery itself. A single cell carbon based batteries will generate 1.5 volts, and NiCad and NiMH battery will generate 1.2 volts.

Answer 5

Chemistry.

The voltage given depends on differences in the electrochemical potentials of the materials used to make the battery. For zinc cells this is roughly 1.5 V. NiMH is about 1.25V.

Answer 6

I think it may be due to charging voltage. As we know the charging voltage must me higher then cell voltage. It is easier to design 1.5v charger then to design 1.7 or 1.8v charger.

Answer 7

Due to the chemical reaction that is what it produces .