Installing a new battery into the WT4911 Siren

Rather you are replacing or installing the WT4911Bat (battery) in the WT4911 outdoor wireless siren, you must follow certain directions.  Failure to follow instructions during this installation process may damage your battery and your siren may not work. When dealing with this certain type of battery, it must go through a depassivation mode.  The purpose of this is to pre-condition the battery so that it won't drop below the minimum voltage of the device once a load has been applied.  This is done by advancing the discharge past the point of the voltage dip. Before connecting your battery in the DSC WT4911, please read and follow theses instructions:

1. Hold the tamper switch down and plug in the battery (continue holding tamper)
2. Continue to hold the tamper switch down for 10 seconds and then release
3. Once the tamper switch is released, the strobe lights on the WT4911/WT8911 will flash different patterns to indicate that it is in depassivation mode.
4. When depassivation is complete, the strobe lights will shut off and the siren will begin to beep three (3) times every five (5) seconds. (Note: It can take the unit up to 30 minutes to fully depassivate.  If at the end of 30 minutes the unit could not depassivate the battery, the unit will stop trying and begin to beep once every (5) seconds.  If this occurs, the battery should be replaced).
5. When the system begins to beep 3 times every 5 seconds, then press and release the tamper switch on the unit.  At this point, the WT4911/WT8911 should flash the strobe lights and beep six (6) times.  The unit is now in the normal power up stage.
6. The WT4911/WT8911 is now ready to be enrolled into your DSC Wireless Alarm Panel, or returned to service.

DSC places a depassivation sticker on all new WT4911 wireless siren that are manufactured.  A pdf copy of the sticker can be seen Here.