It’s a common belief that the voltage of a lithium-ion battery can accurately indicate its charge state. However, this is only partially true. The lithium-ion battery’s voltage increases as it charges, but the relationship is not linear. It can vary based on several factors, including the battery’s age and temperature.
Charging Voltage: This is the voltage applied to charge the battery, typically 4.2V per cell for most lithium-ion batteries. The relationship between voltage and charge is at the heart of lithium-ion battery operation. As the battery discharges, its voltage gradually decreases.
Steady Voltage and Declining Current: As the battery charges, it reaches a point where its voltage levels off at approximately 4.2V (for many lithium-ion batteries). At this stage, the battery voltage remains relatively constant, while the charging current continues to decrease.
Here is a general overview of how the voltage and current change during the charging process of lithium-ion batteries: Voltage Rise and Current Decrease: When you start charging a lithium-ion battery, the voltage initially rises slowly, and the charging current gradually decreases. This initial phase is characterized by a gentle voltage increase.
Key Parameters in Lithium-ion Battery Charging Several crucial parameters are involved in lithium-ion battery charging: Charging Voltage: This is the voltage applied to the battery during the charging process. For lithium-ion batteries, the charging voltage typically peaks at around 4.2V.
When the charge exceeds 3.65V, it is known to be overcharged. Voltage is one of the most important considerations one must keep in mind when buying a lithium-ion battery. It is also recommended that you check out the lithium-ion battery voltage chart to understand the voltage and charge of these batteries.