Battery and charging light

Two Kindle 2's. Both decided to quit taking a charge. Changed the batteries, and when plugged into a charger the charging light doesn't come on, but apparently they are charging. What is my problem with the lights not coming on? Second. Checked the voltage on the batteries. four places to check on the battery. first battery, #4 is ground. #1 shows 2.97 volts. #2 & #3 show no voltage. Battery #2 #1 shows no voltage, #2 and #3 show 2.4 volts. What is going on there?? Any Ideas.