Constant Current – Constant Voltage Charging (CC-CV) is where a battery cell is charged at a constant current until it reaches the maximum charging voltage at which point the voltage is fixed and the current reduced.
The following graph shows this relationship versus charge time.
The constant current charging up to 4.2V is at 0.5C and takes 50 minutes. At this point the cell voltage is at 4.2V and charging switches to constant voltage. In the constant voltage mode the current reduces until it reaches a value at which the cell is determined to be at 100% State of Charge (SOC).
The upper and lower cell limits are determined by a number of factors that go into determining the operation SOC window.
This post has been built based on the support and sponsorship from: Thermo Fisher Scientific, Eatron Technologies, About:Energy and Quarto Technical Services.
The maximum charge current is given by the cell supplier or based on detailed measurements.
Fast Charging of a Lithium-Ion Battery
This work looks at charging current control strategy based on online evaluation of the chargeability status of its cells.
- This protocol is controlled by the ENE< 0V condition.
- It requires access to the negative electrode potential, which must be measured or simulated by means of an electrochemical P2D model.
- It guarantees no Li-plating as ENE is constantly above 0V vs. Li/Li+.
Hi,
Thanks for the information.
I am using a charger that has a current termination of 100mA.
My understanding is that the current in CV mode -and in cc too- is determined by the difference of potential between charger output and battery voltage divided by the resistance.
But the resistance depends of wires, pcb traces, connectors, …
So how to be sure that battery is charged at termination current ?
Regards