A battery is a battery, right? Well, taking a look at this meticulous AA Battery Showdown from BitBox in the UK, it is clear that there is a tremendous variability in power and battery life depending on the quality of construction and a number of other factors, but plotting cost against performance offers unexpected results.
And also take a look at the great resources Adafruit offers to help you to learn about batteries and how they function — to help you choose the right type of battery for your projects.
From the Battery Showdown:
We decided to test alkaline, lithium and zinc-chloride cells to find the best AA batteries you can buy for your money on the highstreet and online. As far as we are aware, this is the largest scale discharge test of consumer batteries that has been performed. The results surprised us a lot.
We are presenting a factual survey of batteries. The selection of batteries is not exhaustive and we have not deliberately included or excluded any brands or manufacturers. We are not recommending any manufacturer or brand based on these results and leave this up to the reader to decide which batteries to buy.