learning about electronics, it is always good to have practical purpose and application. we have the example here of a Ni-MH battery charger as market product in use.
It is looking forward to understand why this charger works and how it works better, at least to understand what is now.
manual logged some experimental data to reveal relationship in between charger and the battery used.
bettery, Ni-MH, capacity 800mAh, AAA, 1.2v, two cells
charger, came along with this phone, previous schematic & photos can be seen here
this is more detail for charger and battery
Ni-MH battery charging, 150mA current initial, slowly goes down as long as battery capacity goes up
7 to 8 hours, battery is considered as full charged, capacity 2.8V
it was an incorrect assumption last time as this time confirmed no constant current for battery charge. it is a simple resistor current limit for charger.
charging rate is 150mA / 800 mA = 0.19 or 20%, 10% is 1C, so 20% is about 2C, 20% charge current for rated battery capacity.