1998 Oldsmobile wont start

Electrical problem
1998 Oldsmobile V6 Front Wheel Drive Automatic 118000 miles

Couple of days ago the van was a little difficut to start, as if the battery was going bad. The next day the van would not start. I put a charger on. Battery reads 12.2 volts. When trying to start the lights come on bright but go out when I turn the key. Thanks for any help.