... 3) 3pcs AG13(4.5v) button batteries (digital watch style), battery life: 4-6months; 4) 2pcs brass security keys( ... seconds and stop suddenly, that means the battery will be worn out, you need to replace ... the battery. 4. When replacing battery, open the lock with the key, ... out the rubber washer, you can replace the old battery, please pay attention to the anode and cathode. ...