I got a Li-Ion battery which has four INR18650MJ1 cells connected in parallel. Since I don't have a charger dedicated to custom batteries, I'm trying to use a bench top power supply.
I saw from internet that it is optimal to charge Li-ion cells in Constant Current mode first and then in Constant Voltage mode. Also one needs to switch the mode when the voltage reach at 4.1V or something.
But here I have a questions. What does the 4.1V mean? Is it the output voltage of power supply, or the voltage at the node between the + terminal of the battery and the + terminal of the power supply? With an output voltage of 4.2V from the power supply, I have 3.5V at the node. In order to maintain CC mode with a charging rate of 0.5C(1.6A), I think I should use 5V or a higher voltage until the actual terminal voltage of the battery goes close to 4.1V. Is it correct?