Full Analysis of Voltage and Capacity of 18650 Lithium Battery.

Full Analysis of Voltage and Capacity of 18650 Lithium Battery.

What is the voltage of 18650 lithium battery? This is a question that many customers and netizens often consult with us. Next, we will provide a detailed introduction to the voltage situation of the widely used 18650 lithium battery.

Lithium ion batteries, whether rated at 3.7V or 4.2V, actually have no essential difference. This is just a difference in the labeling method used by the manufacturer. 3.7V usually represents the typical voltage of the battery during discharge, namely the plateau voltage, while 4.2V refers to the voltage when the battery is fully charged. For common rechargeable 18650 lithium-ion batteries, their voltage is generally marked as 3.6 or 3.7V, reaching 4.2V when fully charged. It is worth noting that this voltage is not directly related to the battery's capacity. The mainstream capacity range of 18650 batteries is from 1800mAh to 2600mAh, while the capacity of power lithium batteries is mostly between 2200 and 3600mAh. In addition, 18650 batteries with a capacity of 3500 or 4000mAh or higher have even appeared on the market.

18650 lithium-ion battery, the pioneer of this lithium-ion battery, originated from a standard model developed by Sony Corporation in Japan for cost savings. In its naming, "18" represents a diameter of 18mm, "65" represents a length of 65mm, and "0" indicates that it is a cylindrical battery. The common 18650 batteries in the market are mainly divided into two categories: lithium-ion batteries and lithium iron phosphate lithium-ion batteries. The former has a voltage range of 3.6V to 4.2V, while the latter has a voltage of 3.2V. In terms of capacity, lithium-ion batteries typically have a capacity of 1200mAh to 3000mAh, while the more common capacity ranges from 2200mAh to 2600mAh.

18650 lithium-ion batteries are known for their high safety factor. They will not explode or burn, and are non-toxic and harmless. They have been certified by the RoHS brand to ensure green environmental protection. In addition, its excellent high-temperature resistance enables the discharge efficiency to reach 100% even under 65 degree conditions. To further prevent battery short circuit faults, the 18650 lithium-ion battery adopts a design where the positive and negative poles are separated, minimizing the possibility of short circuit faults. At the same time, installing a lithium battery protection board can prevent overcharging and overdischarging of the battery, thereby extending its service life. In terms of voltage, 18650 lithium-ion batteries have multiple options such as 3.6V, 3.8V, and 4.2V, which are much higher than the 1.2V voltage of nickel cadmium and nickel hydrogen batteries.
The capacity of 18650 batteries is not directly labeled on the battery cells, but is distinguished by the color of the positive electrode cap. During the discharge process of the battery, gas will be generated. For safety reasons, the positive electrode of the battery is equipped with a protective cover. When the battery discharge reaches the upper limit of the design life, the gas will push open the outer cover, causing the battery to automatically disconnect and ensure safe use.