[dragontamer]

It doesn't really make sense to buy a $20 charger when you only have $16 or so worth of AA cells (ie: a 16 pack from Amazon Basics). The $10 charger makes a lot more sense.

As for the knowledge problem: that's easily solved. I already told you what to do so you know how to work the $10 charger now. If you still want the $20 charger that's fine, it's your money.