No, this is not normal. Under standard use, the batteries in Digitest 3 should last for several weeks to months, depending on the frequency of testing. The replacement battery may be a Duracell ® MN1604, Panasonic ® 6AM6 or equivalent. Although rechargeable 9-Volt batteries may be utilized, they will require more frequent charging because of the considerable voltage required to perform the pulp vitality testing procedure.