Specifications – What should you look for
Internal use: Most battery powered wireless alarms (referred to here as Emergency alarm systems) are suitable for internal use providing the premises is weather tight. By weather tight we mean that it has 4 walls, a good roof and all windows and doors etc. If there is a risk of significant drafts, many of these systems will false alarm regularly. In these instances, we strongly advise using an externally rated emergency alarm system to avoid false alarms.
External use: There are very few battery powered wireless security systems available to buy that are designed to work externally and these are generally more expensive than internally rated systems. In these instances, the RDAS GSM, RDAS GPRS and VX GSM systems from Compound Security are probably your only reliable choices.
Battery life: The more often your emergency alarm system activates, the more text messages and voice calls it will make. This will have an impact on the battery life of the system, especially if you have set it up to alert many different people each time.
Manufacturers usually quote battery life of around 1 year, however, this is usually based on something like one status message each day and one activation per month and a message to one person. Given the choice, do not use a rapidly deployable security system with less than 1 years battery life, as even this could end up being 6 months if high usage occurs. Obviously you can change the batteries, but that may not be practical in certain situations.