My radio controlled clock has stopped working.

It takes a single AA battery, all the ususal suspects in my house now uses
triple As, so where can I buy a single AA battery?

All I can find is packs of 4 (actually as they are a BOGOF, in packs of 8)
and all I can use is one! Even with a shelf date of 2016 I won't get
through them before they die (though experience tells me that the dates are
optimistic).

How environmentally friendly is it to insist that I buy 4 to throw three
away?

(Just out of interest, as there are packs of 20/40 available, what devices
do still use these batteries?)

tim