What is the best way to charge a Li-ion battery?

Charge at 1C (2500mAh battery charge at 2500mA). Will take like an hour in this phase from completely discharged to around 3/4

Charge at that current until voltage reaches set maximum. Then keep the voltage constant for one more hour for full charge (optional).

Set maximum like that (not LiFePo cells, most regular Li-ion batteries):

4.0V – very long life – years and thousands of cycles.

4.1V long life – years

4.2V normal – few years, 200–500 cycles.

4.3V short life – up to a year, few hundred cycles.

4.4V very short life – you need maximum capacity immediately after charge, will replace battery after 50–100 cycles.

Charge up to 4.0V for everyday use (one cycle or more per day).

Charge up to 4.1V – use on the same week

Charge up to 4.2V for immediate use (same day).

Do not charge for storage. Keep voltage up to 3–3,5V for long term storage.

Don’t discharge below 2.5V