Various Uniross Batteries are on offer with Buy 2 Get 1 Free.
You can have AA or AAA for example. Full details on the site.
For example, you can get 2 x 10 packs of AA plus 1 x 10 pack of AAA for what seems to be a great price of £3.98 for 30 brand name batteries delivered.
MyMemory site is wrong and the Uniross site is not - these really are Zinc, not Alkaline as MyMemory suggests. Sorry for the Alkaline in the original title.