Batteries should be changed about every ten to 14 days. The exact schedule for changing batteries depends on the amount of time the hearing aids are worn and the power consumed over time. Most new digital hearing aids have battery warning indicators. Before the battery goes out, the hearing aid will "beep, beep, beep" to tell you you have another hour or two before the battery fails. Using excellent, fresh batteries is important, and changing batteries should take no more than 60 seconds.