Battery back up sirens are an extremely important part of a premium alarm installation. Importantly, these sirens will continue to sound if a thief removes the vehicle's battery leads. Internally the siren switches to it's own battery for it's source of power and continues to provide protection for your vehicle. Battery back up sirens come in two main types with significant differences.
Digital Battery Back Up Siren
Digital Battery Back Up Sirens are connected to the vehicle's alarm module via a data wire. This means they know when the alarm is armed or disarmed, providing some key benefits. Firstly, there is no need for an over-ride key, which means the siren can be hidden well out of the way of thieves. Secondly, if the battery is disconnected when the alarm module is disarmed, the siren will recognise this and won't go off (your mechanic will thank you!)