How to detect how many mAh a battery is?

Hello,

This is my first post, and I think I finally found the right forum for my question

When I buy AA batteries for example, how do I know the AA (mAh compacity)? If it doesn't say it on the box, can I get a basic tester to tell me this? I saw an older thread from 2004: http://www.candlepowerforums.com/vb/showthread.php?64660-Alkaline-Battery-Shoot-Out

Are AA Alkaline batteries today in 2012 still the same as they were 8 years ago for the most part?

Thank you for your help.

The only way to test it, is to discharge it with some device capable of doing it. Silverfox states he used a "West Mountain Radio CBA" to do this. It's a relatively expensive device. The popular Maha C-9000 charger also has a Discharge function that can be used to test the capacity.

I just looked up the "Maha C-9000 charger", but it seems like it is only for rechargeable batteries? I want to do a test of 10 different brands for AA type, and I wanted to know the easiest way to test regular Alkaline batteries.

I bought a Doc Wattson Analyzer that may be hooked between almost any DC source and load and reports on seven parameters. It is used by folks to monitor their solar power systems and to determine which devices actually use the least power. The hobby RC community uses them to determine whether engine load curves are compatible with battery discharge curves... It is a handy device which may be patched between a cell or battery and a load to determine actual performance. With a ~$60 price it is not cheap but it is a very versatile tool which may be used by many in different ways for many different applications and it's much cheaper than many of the other hobby RC gadgets.

I'd be lost without mine. I have stuff in the mail right now that I will be testing with the DW in the next few days so that I may determine how long I may safely run them without damaging my AGM SLA batteries.

The Doc Wattson may determine exactly how many mAh may be had out of any cell.

It's a powerful tool.

C-9000 in discharge mode can compare Alkaline batteries too. Obviously you shouldn't try recharge them. Hobby chargers also have various discharge functions, and I've also used those for testing alkaline batteries.

Alternatively, if you just want to know how various alkalines perform, take a look at pre-made tests at http://www.batteryshowdown.com/