Battery Backup
The length of time that a backup battery will last depends on the power consumption of the
system.
The main factor here is the power consumption of the locks. A Fail-Safe (Fail Open) lock
requires current continuously while a Fail-Secure (Fail Closed) lock only draws current when
it operates. You need to estimate how often the lock will operate and then use the following
equation to estimate consumption:
Consumption = Lock Current × (Operations per hour × lock release time) / 3600
Example
A 500mA lock operating 100 times an hour for 5 seconds would use 500 × (100 × 5) /
3600 = 69mA per hour.
Once the total power consumption has been estimated then it can be calculated how long
the fully charged batteries will last. The Ah rating of batteries is usually given as a 10 hour
discharge rate. If the batteries discharge over a shorter period of time they will last for less
than their quoted capacity.
Example
An Easikey 250 with two readers and two continuous (Fail-Safe) locks each drawing
250mA would consume 190 + 90 + 90 + 250 + 250 = 870mA. A fully charged
12Ah battery would last 12 / 0.870 = 13.7 hours.
Readers
Install readers according to the instructions supplied with each reader. Readers are usually
installed at about door handle height on the unhinged side of the door.
All readers have the same wiring terminals, and are fitted with a green LED that illuminates
when access is allowed, and stays illuminated for the duration of the lock release time.
The maximum distance of a reader from the controller is 100m.
If two readers are fitted then they must be at least 300mm apart.
The Easikey 250 is compatible with OneProx readers and Easikey readers.
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