Is There a Way to Measure when a Ni-Cd Power Pack is Fully Charged?
NiCADs and NiMH both have the property that, at constant current charge, when they reach full charge they will show rapidly rising voltage. Rapid temperature rise, too, although standard NiCAD chargers will operate at a pretty relaxed (nominal 16 hours) charge regime, so temperature isn't a problem. This is not true of fast-charge NiMH, and temperature sensing can be important in terminating such chargers.