I think we have Lithion Ion Rechargable Batteries (A3 or A4 format) as well. This technology is used in from Notebook Computers to Mobile Phones, they have the highest capacity (Lithion Ion>NiMh>Alkaline>Nicd..). I have seen it in London Drug, too. P.S.: Just a suggestion. NiMh is sufficient for your everyday use, so just buy whichever comes handy.