Automated test using two AAA alkaline cells of each type. Done in February 2016 and with results consistent to the results of other tests, which are also shown on YouTube.


YouTube video  


The test rig is described in the first minute of the video. There is a PC interface for voltage measurements and from which the other data is derived. A temperature sensor was included. The mechanism in the top right is a motor with current-draining resistors in parallel, and a rotary encoder for further feedback to the program on the status, and a warning of when the motor had stopped turning. The timer is a quick provision of relay control and for checking of test duration:



Results page: 



Total Power Supplied (Varta High Energy not on graph):


At the time of testing the most powerful were (in watt-minutes for the two cells):


Panasonic Pro Power (114), Fusiomax Endurance (101), Kodak Ultra (98), Varta High Energy (97), Duracell Plus Power (97), Kodak Xtralife (93), Energizer ECO (89), Sony (85), Polaroid Super Alkaline (69).


These figures are complicated by price and variance of price. The unanimous findings are that Kodak Xtralife at 6 for £1 are by far the best value for the buyer. Fusiomax Endurance at 4 for £1 are a serious contender and only one of the two above 100 watt-minutes for the pair. A few months after the test I found an offer in Morrisons supermarket, the Panasonic (highest performance) AA cells were 24 for £8 and Argos had a similar good bargain for the Panasonic AA and AAA. 


In this test the measurements ended when the total voltage was reduced to 0.5V, this coincided with total failure of the cells. It is interesting to see in the video that zinc-carbon cells are not totally destroyed at this point, and will self-recharge. Their watt-minutes per £1 from discount stores is higher than many alkaline, including Duracell's best price (2 for £1). 


One of the tests when finished: