Why is it that we use voltages and watts more often than amperages? 9v batteries, 12v car battery, 1000W Microwave oven. But amperages not so much, even though its “half” of what makes power, A*V=W. What property of amperes makes it so “unnecessary” to be aware of?
Bonus: how many amps and volts does a typical 1000W microwave use?
Batteries have both electron capacity (cumulative) and current capacity (rate) ratings. The chemistry and size determine how many electrons (aka Amperes times hours) can be stored, and the conductor sizes (including within the cells) determine how quickly it can be charged or discharged in sustained operation (without permanent damage).
A car battery can be shorted with a screwdriver and discharged at a high current, but only for a short time without damage to the cells. A 100Ah car battery can supply rated current for roughly twice as long as a 50Ah battery.
Sometimes people call these ratings energy and power ratings by multiplying each by rated voltage, but the voltage does vary with charge state and rate of current flow so those “ratings” are rather approximate.