lord loh. said:
Okay, I tried to charge the battery using a constant current source.
My target is two Ni-Cd 700mAh cells in a series, I used a 23.5ohm resistor in a series and the source voltage of 3v. The initial voltage was2.29v and my target is (1.35v x 2) = 2.7v
The initial charging current as measured was 26.7mA and reduced to 16mA within the first 10 minutes. This reduction included a lot of fluctuations. The current reduced to as low as 14mA and increased to 20mA during this period. After this the charging current decreased steadily. The battery temperature remained at room temperature.
After 40 minutes, the target battery voltage was 1.62v and current 14mA.
Can anyone explain me this phenomenon and enlighten me with their comments?