The batteries in the Breeze fingerprint internal door lock should last roughly 6 months, so once they have run out you will need to replace them. You will also receive low battery warnings for approximately 200 operations before the batteries die. Blusafe Breeze biometric locking systems come with a key for this very reason. When your lock has no power, it can still be opened with a spare key or connected to a Micro USB port using a spare power supply and unlocked with a fingerprint. If you believe your product is faulty, or isn’t working perfectly on new batteries, contact us for assistance and we will respond as soon as possible.