As far as testing a battery, Use the 10Amp (or greater) scale on your meter. Put the red probe to the positive battery terminal and the black to the negative. A good AAA to D cell will show at least 2 Amps. This is what would be called a destructive test, do not leave the battery connected to the meter for longer than to read the meter. The meter won't be harmed, but you are discharging the battery at a high rate. Just a quick test is OK.