These are two different batteries:
1. The 1.5 volt battery is a primary battery and cannot be recharged. It is classified into alkaline and acid batteries.
2. The 1.2 volt battery is a rechargeable battery that can be used repeatedly. It is divided into nickel-cadmium and nickel-metal hydride.
Currently common rechargeable batteries are nickel-cadmium batteries and nickel-metal hydride batteries, both of which have terminal voltages of 1.2 V. Lead-acid batteries are 2 V, Rechargeable lithium batteries are 3.6 V and zinc-manganese dry batteries are 1.5 V.
The open circuit voltage of a rechargeable battery (the potential difference between the positive electrodes and negative when not discharged) is determined by the positive and negative electrodes of the battery and the electrolytic material. This is determined by the electr reactionochemical of different materials. In other words, as long as the materials of the positive and negative electrodes are the same, the voltage will be the same regardless of the size or capacity of the battery.
And 1.5V/1.2V is just a nominal voltage, not an actual voltage. For example, a 1.2V nickel-chromium or nickel-metal hydride battery is nominally 1.2V when fully charged, it is 1.4V or even more, and when discharged, it can reach 1 V.
Detailed information:
Acid batteries mainly useipally an aqueous solution of sulfuric acid as a carrier, such as zinc-manganese dry batteries (some consumers also call them acid batteries), seawater batteries, etc. ; medium batteries, such as lithium batteries, lithium ion batteries, etc.
The second category, divided according to the nature of the work and the method of storage, includes: primary batteries, also called primary batteries, that is, batteries that cannot be recharged, such as zinc-manganese dry batteries, lithium primary batteries, etc. ; secondary batteries, namely rechargeable batteries, such as nickel metal hydride batteries, lithium ion batteries, nickel cadmium batteries, etc., generally referred to as lead acid batteries, which are also secondary; fuel cells.
The third category, divided according to the positive and negative electrode materials used in the battery, includes: batteries ofzinc series, such as zinc-manganese batteries, zinc-silver batteries, etc. ; such as nickel-cadmium batteries, nickel-hydrogen batteries, etc. : lead-acid series batteries, such as lead-acid batteries, etc. ; lithium-ion batteries, lithium-manganese batteries, such as zinc-manganese batteries; , alkali-manganese batteries, etc. ; air (oxygen) series batteries, such as zinc-air batteries, etc.
Battery voltage is related to the material of manufacture. For example, zinc-manganese dry batteries are 1.5 V, lead-acid batteries are 2 V, and lithium batteries are 3.6 V. Commonly used rechargeable batteries are nickel-cadmium or nickel- metal hydride and their standard voltage is 1.2 V.
Rechargeable batteries are rechargeable batteries with a limited number of charges and are used with chargers. The market generally sells No. 5 and No. 7, butthere is also number 1. The advantages of rechargeable batteries are that they are economical, environmentally friendly, have sufficient power, and are suitable for high-power and long-use electrical devices (such as portable music players, electric toys, etc.). Powered by rechargeable batteryThe voltage is lower than that of disposable batteries of the same model. AA batteries (AA batteries) are 1.2 volts, and 9V rechargeable batteries are actually 8.4 volts. Today, the number of recharges is usually around 1,000 times. As of February 2012, there are only five types: nickel-cadmium, nickel-hydrogen, lithium-ion, lead-acid and iron-lithium.