Except for obscure hearing aid and special purpose batteries, virtually any regular battery from standard D-cells to tiny camera and watch batteries can be found in St. Petersburg. To save time and money, however, best bring special batteries with you. Imported alkaline batteries tend to be expensive. A small inexpensive ($3-4) 220 volt transformer with a voltage selector (1.5V, 3V, 4.5V, etc.) can be used to power portable audio players, etc.