For lithium batteries, a good charging current is generally between 0.2C and 1C, with 0.5C being a commonly selected balance between charging time and charging safety. Most constant-current charging currents fall within this range.
The charging time for a battery, given the charging current, is about 2.5 to 3 hours. The charging current for a common Panasonic battery, type 18650 and 3500mAh, is 0.2C-0.5C, or 700mA-1.75A. For a power type Samsung battery, type 18650 and 3000mAh, the charging current is 1.5A-3A. Note that this passage does not directly provide the answer to the exact charging time for a specific battery, but it does give the relationship between charging time and charging current.
Charging Time of Battery = Battery Ah ÷ Charging Current T = Ah ÷ A and Required Charging Current for battery = Battery Ah x 10% A = Ah x 10% Where, T = Time in hrs. Example: Calculate the suitable charging current in Amps and the needed charging time in hrs for a 12V, 120Ah battery. Solution: Battery Charging Current:
To calculate the charging time for a lithium battery, divide the battery capacity by the charging current and add 0.5-1 hours at the end. The charging current is usually marked on the charger.
Customers often ask us about the ideal charging current for recharging our AGM sealed lead acid batteries. We have the answer: 25% of the battery capacity. The battery capacity is indicated by Ah (Ampere Hour). For example: In a 12V 45Ah Sealed Lead Acid Battery, the capacity is 45 Ah.
When a battery is fully charged, the charging current drops to 0.1C. The circuit switches to constant voltage charging mode once the voltage achieves its maximum, charge cut-off voltage. The charging current of the battery steadily lowers down, and the charging rate slows down when the voltage is sustained at charge cut-off voltage.