Alkaline battery comparison

How good are the cheap and expansive batteries? I'm buying a lot of batteries for the toys of my children. Most of the time the cheap versions like Panasonic form the Action, Alkalisk from Ikea and Lidl. There are only a few battery manufactures in the world, so these batteries are coming probably out of the same factory. So what are the real differences?

To do the comparison i have acquired a load tester from eBay to drain the power controlled from the cells and log them to compare. 

In the near future i will publish the results on this page.