Typically, you charge lithium batteries by applying the CC-CV scheme. CC-CV stands for Constant Current - Constant Voltage. It denotes a charging curve where the maximum allowed charging current is applied to the battery as long as the cell voltage is below its maximum value, for example, 4.2 Volts.
This target charge current is relative to the battery capacity ("C"). For standard Li-ion or Li-polymer batteries, chargers often target 0.5C charge current. In other words, if the battery is rated at 500 mA-h, the target current is 250 mA. It is not unusual to charge at 1C (500mA), but this compromises the battery's capacity over time.
The standard charging protocol for lithium-ion batteries is constant current constant voltage (CCCV) charging. In addition to this, several alternative charging protocols can be found in literature. Section 2 will provide an overview on the different categories of charging protocols and their specific characteristics.
Discover the optimal charging voltages for lithium batteries: Bulk/absorb = 14.2V–14.6V, Float = 13.6V or lower. Avoid equalization (or set it to 14.4V if necessary) and temperature compensation. Absorption time: about 20 minutes per battery. Ensure safe and efficient charging to master battery care and optimize performance.
During the bulk charging phase, lithium batteries need a controlled charge at a specific voltage level. This ensures equal charging across cells, preventing imbalance issues within the battery pack.
Use a charger capable of adjusting charging voltage based on temperature changes. Protects lithium batteries from potential damage by accounting for variations in internal resistance during temperature fluctuations. Consider factors like capacity and charge rate to determine the appropriate charging time.