BATTERY VERSUS PLUG-IN POWER

Plug in Power

If you think about it plugs are, by design, meant to be easily unplugged. With an alarm system however that compromises their reliability. This can happen so many ways:

* If an operator is annoyed with an alarm, they can simply yank the plug to silence the alarm, sometimes this is well-intentioned and they intend to come back later to fix the alarm condition, but people do forget.
* Sometimes an outlet is desperately needed for some emergency so it is "borrowed". Can you count on the fact that the alarm will be plugged back in?
* Sometimes plugs are tripped on, or snagged, and come unplugged inadvertently.
* The circuit breaker for a branch power line can trip and not be noticed if nothing important is on that line.
* Power outages are a time when alarms are most needed because thats when pumps stop pumping and normal protections may not be there. Even when power returns, many systems need to be reset before operating again. This is the time when fuses often tend to blow because of the abrupt shutoff/startup surge.

Battery Power

Battery power by comparison, can only become fail if someone unscrews the electronic enclosure and willfully disconnects the battery. Of course batteries eventually discharge. So a good way to deal with this is to add a battery change to your factory PM schedule to change the batteries as needed. If you don't have a reliable PM program, call Gizmo Engineering and we'll be glad to send an automated message when its time.

Best Choice?

We think battery power is the better choice unless:

* your usage is high enough that necessary battery changes occur too frequently. (more than once a year)
* You don't have a PM system to ensure battery changes.

In these cases plug-in power might be a better choice for you. Can't decide? We'll install a power jack (at no charge) so you can use either.

How Often to Change Batteries?

The capacity of a single Ultralife Lithium battery is 1200 milliamp-hours, and the current draw during alarming is 25mA. (There is zero current draw unless the unit is actually alarming) So, 1200/25=48 hours of continuous alarming.

Based on this, a conservative rule of thumb on when change batteries is below:

Alarm Frequency.........................Battery Change Frequency

Several Daily.....................................1 year

Once Daily.........................................2 years

Once Weekly.....................................4 years

Once Monthly....................................6 years