Standalone electromechanical locks require battery power in order to operate. Most network-capable, standalone electromechanical locks have a battery condition indicator. As the battery in a networked lock begins to reach replacement, the software can usually notify this condition. This simplifies the process of battery replacement.
However, for non-networked locks, the story is very different. The average lock manufacturer designs locks with sufficient battery power for at least one year plus a margin of safety. Most lock manufacturers recommend replacing their batteries usually once a year.
Different electromechanical locks can have different sizes and numbers of batteries to ensure at least one year of normal operation. However, depending upon the actual number of operations (cycles), the batteries may either need to be replaced sooner or may last longer than one year.
Power draw and the resulting battery life is dependent upon the functionality and operational features of the electromechanical lock. For example, the Samsung EZON Digital Keypad Deadbolt has a stated battery life of 3,650 operations for the two AA batteries. The lock’s power requirement was designed around 10 operations a day for this touchscreen, motorized deadbolt lock. When the correct code is entered, a motor engages and retracts the one-inch throw bolt. When leaving and closing the door, the motor again engages and extends the bolt one inch. The motorized bolt requires a significant amount of power in addition to the power requirement of the touch screen and the electronics.
The Arrow Revolution is also a touchscreen operated lock. However, the Revolution has a battery life of approximately 20,000 cycles for the four AA batteries.
Note: Some lock manufacturers list the number of openings or cycles an average electromechanical lock can operate during the life expectancy of the batteries. Others indicate the number of years of operation using one set of batteries.
For non-networked locks, there are three general methods for determining battery replacement. The first method is checking the batteries at a regular interval by walking up to each lock, removing the batteries and determining their condition. This method requires a great deal of time and labor.
The second method is preventative replacement at a set time interval. If the facility has many electromechanical locks, preventative replacement may be the best method.
The third method is to depend upon the “low battery” warning. The premise is that someone will notify you either that there is a sound coming from the lock or it is unusually slow to unlock. Or the other possibility occurs. You get an angry telephone call notifying you that people are locked out and cannot gain access.
There are different methods devised by lock manufacturers to notify of low battery condition. The commonality is that when the batteries are in need of replacement, the lock will do something -- flashing LEDs, beeps or tones, slow the lock unlock time, etc.
The Samsung EZON Digital Deadbolt Lock has an interesting method for notifying when the batteries need replacing. When unlocking the lock, the melody “Blues for Elise” sounds. This is the indicator the batteries have been depleted to the level of requiring replacement. The batteries must be replaced within approximately one week of hearing this melody. If the batteries are not replaced, the lock will continue to operate and play the melody until the lock fails to operate.
Most standalone locks have a key override that is used when the batteries are dead or the electronics are no longer operating. If there is no key override, most of these locks have contacts or a port to accommodate a backup (usually a nine volt) battery. Providing power should permit a User Code to be entered and to unlock the lock.