Quote Originally Posted by tkamiya View Post
... It may be holding decent charges for weeks and months, and die very quickly in a way it discharges very fast one day...
Don't forget that a NiCD battery has a sharp "knee" in its characteristic discharge curve as compared to other types of batteries. Under normal conditions, they will go for as much as 70% of their useful per-charge life span then suddenly loose power. Other types of batteries gradually lose power over the length of their discharge curve. Further, that "knee" gets even sharper as the battery ages.

An old, worn out or overcharged NiCd batter can literally work well for a few minutes when freshly charged then suddenly die off in a matter of seconds.