Difference between 357 and 357A button battery?

Answer 1

The 357 (ENERGIZER 357/303H) is a silver oxide battery with a relatively constant voltage during its life until the voltage drops off sharply when it dies. A standard replacement is SR44. The 357A is an alkaline battery the voltage of which drops slowly and constantly during its life. There are also silver oxide versions of this cell (ENERGIZER 357/303) with similar voltage characteristics. A standard replacement is the LR44. Practically, if your device is more demanding of its battery (for example, fancy calculators and measuring devices), use the 357, if it is less demending, you can use the 357A. If you try a 357A, and your device doesn't run very long on it, then it is more demanding, and you should switch to the 357 next time you get new batteries.