What's wrong with my Dewalt batteries/charger?

[gdocktor3]

I have two 20v Dewalt batteries that only charge 2 out of 3 bars. One is a 3.0ah I bought brand new and the other is a 1.5ah that I got from a relative for free, but it's only a few years old with very little use on it. I bought a small charger off eBay brand new and it reads fully charged at 2 bars and goes into maintenance mode. The 1.5ah was fully charged at 3 bars when I acquired it, so I'm thinking its a problem with the charger? Why would this happen? I think it's the dcb107 charger.

 

[MDSPHOTO]

Old, New stock battery and used battery? My wife bought me a Dewalt for Christmas one year and the box had a thick layer of dust on it. Within 3-months the batteries wouldn't fully charge or wouldn't hold the charge. Called Dewalt, gave them the numbers on the drill and they explained that unit had been sitting there for a few years and sent me a new battery.

 

[gdocktor3]

Nobody else has had this problem?

 

[areyouanywhere]

I have seen Ingersoll Rand batteries do this, I opened it up and a connection to one cell was not properly welded/soldered.