RE: 6V Charging
It depends on the output of a wall wart. If it is over 7.5 volts it will charge the battery. Some wall warts are, some aren't. I guess that I should have said that in my first post. I am sorry that I didn't clarify that point. But if the charger doesn't put out voltage as high, or higher, than the max voltage of the pack you will never be able to completely charge it.
Ken