Hearing Aids will drain the battery when not in use. To ensure longer battery life, open the battery door when you remove your Hearing Aids from your ears.If you do not wear your hearing aids for several days, take the batteries out of your Sontro OTC Hearing Aids.You can see how much battery life is left on your hearing aids on the Devices page of the otoTune app.Do not leave a dead battery in the hearing aid; change it ASAP.Remember to keep track of your batteries carefully. They are dangerous if small children or animals swallow them. Should this happen, seek medical attention immediately.