Battery & Charger Question

[APHCO]

I have a drill that came with two batteries and one charger. How would I test to see if the batteries are not accepting/holding a charge or if the charger is not properly charging.

Are there electrical readings that can be taken from the charger that will indicate the proper output? Or maybe the batteries are no good.

This is an 18V. system and when putting the batteries on the charger it indicates a "soft charge" where both the green and yellow lights are lit. It never goes to solely green and the battery does not charge fully.

[Velosapien]

What brand/model is the drill? That info can help. Someone with experience on the same model will have something to compare to. What problems are you actually having with it? Do you find it doesn't seem to run long enough? It's fairly tricky to tell the condition of a battery because even a deteriorated battery reads the same voltage when you charge it. It just drops off a lot faster under load.