I've been reading a lot, here as well, and from what I understand, your garden variety battery meter isn't truly accurate for telling you the voltage of a common household use battery at any given time (AA, AAA, C, D, 9V, and button cell). This is due to no load being placed on the meter while you test a battery. The load, if I've read correctly, gives you a more accurate understanding of what a battery can do in an actual real-world application.
So, I'm trying to buy a device that cheaply tells me what any battery I have is able to output but I don't want to buy something that only gives me a superficial inaccurate reading. Does the device I want exist or is it something I'll have to assemble out of different components like a resistor, etc?
Thank you for any help and for anything I can get from you to learn this better! You'll have to go easy on electronics fundamentals if you're going to explain concepts to me. :)