alarm systems which barely sip energy?

Scenario: you and your family are on a long vacation half-way around the world.  You get a message from your alarm system (or monitoring company) that main power has failed.
 
Now what?  If you have  a typical alarm panel and a typical backup battery, your alarm system will be dead in a few hours if main power remains offline.  Say that happens.  Then what are you going to do?  Your house is now un-monitored.  As you ponder the vulnerability, you realize all the crooks  probably learn about this weakness in alarm systems in the first five minutes of crime school.  All your warm feelings about having an alarm system monitoring things are vanished.  Happy vacation.
 
Are there alarm systems which can run for months, instead of hours, on the same amount of backup power?  Or do any of the existing systems have super energy-saving modes that could accomplish that which they can switch into when main power is lost?
 
 

I don't know of any low power systems, but it's an interesting idea, and maybe a very low power system could be designed. But I suspect that the manufacturers don't have a whole lot of motivation to do it.
 
With existing systems, I think the only way to extend the run time would be to dump the active devices that consume power, like PIRs and glassbreaks, leaving just the more passive devices, like window and door contacts for perimeter protection.  But even these cause the panel to use some small amount of power, say 5mA per zone.  If you dumped the active devices, you might be able to keep things running for a couple of days, depending on the size of your battery and the number of active devices you have.  But I don't know of any system that could run for weeks or more.

I bet you could run a typical system for days on a standard computer UPS.
 
This seems like a rather impractical scenario, though -- where do you live that you have to be concerned about power being out for more than a couple days, max?

tadr said:

I bet you could run a typical system for days on a standard computer UPS.
 
This seems like a rather impractical scenario, though -- where do you live that you have to be concerned about power being out for more than a couple days, max?

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A standard UPS will likely give you less run time for an alarm system than the alarm system's own backup battery would, as the UPS is less efficient, given that it converts power from a 12VDC battery to 120VAC for the alarm, which then converts it back to 12VDC.
 
In my rural area of the northeast, we have, on occasion, lost power for 2-7 days due to ice storms, early or late season snow storms, and hurricanes. In a 30 year period, this has happened to us about 5 or 6 times.  I can understand why some folks might want a way to power their system for more than a few days.

tadr said:

This seems like a rather impractical scenario, though -- where do you live that you have to be concerned about power being out for more than a couple days, max?

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The scenario I was thinking of was sabotage: it could be as easy as someone walking up and throwing the main breaker switch.  There are probably other ways also that I'm not devious enough to imagine.  In that case, the power isn't going to just come on by itself.  It's off until you get back from vacation.  If you're psychic, you might send in an electrician while you're gone to troubleshoot the cause.  Who among you would do that?

RAL said:

With existing systems, I think the only way to extend the run time would be to dump the active devices that consume power, like PIRs and glassbreaks, leaving just the more passive devices, like window and door contacts for perimeter protection.  But even these cause the panel to use some small amount of power, say 5mA per zone.  If you dumped the active devices, you might be able to keep things running for a couple of days, depending on the size of your battery and the number of active devices you have.  

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That's why I thought perhaps some systems might have a "mode" they could shift into that would shed those types of devices.  For convenience  I have half a dozen keypads, and they seem to consume a lot of power.  I certainly don't need them all to be powered on during a power outage.
 
As for the alarm panel's microcontroller, it could put itself to sleep and only wake up when it senses a transition on one of the I/O pins. An arduino can do that. It's one of the tricks that lets them run months or years on a coin cell battery.

NeverDie said:

The scenario I was thinking of was sabotage: it could be as easy as someone walking up and throwing the main breaker switch.  There are probably other ways also that I'm not devious enough to imagine.  In that case, the power isn't going to just come on by itself.  It's off until you get back from vacation.  If you're psychic, you might send in an electrician while you're gone to troubleshoot the cause.  Who among you would do that?

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I guess I'm not terribly worried about sabotage. But there are other things that could cause the power to go out, perhaps just to my house and not anyone else. 
 
My electric utility has online maps showing power outages in real time, and allows online reporting of power outages as well. If I received a notification from my alarm system that the power was out, that's the first thing I would check.  If the utility company wasn't aware of the outage, I would report it, and if it wasn't resolved in a few hours, I would phone a neighbor to have them check on things.  If the problem was on my side of the meter, then yeah, I probably would call an electrician while I was away.

The problem that you will face is that each zone requires current, not only to power motion sensors and other sensors, but also to provide current for the EOL resistor. This can be around 5ma per zone, so for 20 zones, that is 100ma.
 
If you are terrible worried you could get some 25AH marine batteries and wire them together. that should at least get you to around a week. 

A pair of 6volt 225AH Golf Cart batteries in series 
 
Will need a separate charger.

FACP's have the design down, 200 aH are commonplace on larger (single, non-networked) systems. Hell, they even make the cans and racks for them.
 
The design issue is going to if the system supervises bus devices, loadshedding isn't really an option for most. Dumb system, sure.

NeverDie said:

The scenario I was thinking of was sabotage: it could be as easy as someone walking up and throwing the main breaker switch. 

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You mean you don't have your breaker box/panel door monitored with an 'instant' alarm (our breaker panels are accessible from the outside of the house here)?  I also do this on the side access panels for the phone/cable as well.

ano said:

The problem that you will face is that each zone requires current, not only to power motion sensors and other sensors, but also to provide current for the EOL resistor. This can be around 5ma per zone, so for 20 zones, that is 100ma.

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You raise a good point.  For zones with powered sensors, there may not be much you can do other than find sensors which consume less power.  As semiconductor dies get smaller and chip voltages drop, a sensor based on newer chips but with the same functionality could conceivably use a lot less power than older sensor designs.  Right?  
 
For zones that aren't powering sensors, would the 5ma current have to be continuous?  For example: a zone that's just a door/window magnetic reed switch.  If short pulses would suffice (say a 10ms pulse every 200ms), wouldn't you save a lot of power, because 95% of the time the current would be OFF?

BraveSirRobbin said:

You mean you don't have your breaker box/panel door monitored with an 'instant' alarm (our breaker panels are accessible from the outside of the house here)?  I also do this on the side access panels for the phone/cable as well.

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Excellent point.  The more clues the better.  However, until someone acts on that information to undo the sabotage, your house is only monitored until the backup batteries are exhausted.  If a thief tripped the main breaker and then padlocked the panel, all you have is an inference, not a smoking gun, that something is rotten in Denmark.  Would the police even visit if all you have to report is a tamper alarm and a power failure?  And if they do visit, they won't be able to see or deduce much, so off they go until the next alarm.  Except there won't be a next alarm, because in ~4 hours (and most likely a lot less) from the time of sabotage, the alarm panel will have burned through its backup power and will be dead.  At that point, until someone undoes the sabotage,  your house is essentially defenseless.  Am I right?  Or is that not what would happen?

ano said:

If you are terrible worried you could get some 25AH marine batteries and wire them together. that should at least get you to around a week. 

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Yup.  I figure I'd need fewer expensive backup batteries though if the alarm system could first be configured to use a lot less power--if not all the time, then at least during a power outage.  However, at least based on the posted answers so far, more energy efficiency doesn't seem to be an option, aside from maybe upgrading powered sensors to more energy efficient equivalents (and the possibility/viability of even that  is so far just sheer speculation on my part).
 
To me it just seems rather pathetic if an alarm system could be so easily defeated.  I would have thought that an alarm system, because of both its very nature and its intended function, would be designed to withstand such an obvious attack.  If not, I'm flabbergasted. 

NeverDie said:

Scenario: you and your family are on a long vacation half-way around the world.  You get a message from your alarm system (or monitoring company) that main power has failed.
 
Now what?  If you have  a typical alarm panel and a typical backup battery, your alarm system will be dead in a few hours if main power remains offline.  Say that happens.  Then what are you going to do?  Your house is now un-monitored.  As you ponder the vulnerability, you realize all the crooks  probably learn about this weakness in alarm systems in the first five minutes of crime school.  All your warm feelings about having an alarm system monitoring things are vanished.  Happy vacation.
 
Are there alarm systems which can run for months, instead of hours, on the same amount of backup power?  Or do any of the existing systems have super energy-saving modes that could accomplish that which they can switch into when main power is lost?

Click to expand...

 
 
A standby battery usually supply power to the security systems in case the main power failed. However, its duration varies on the power usage of the system and the condition of the battery. 
 
In that case, the best thing that you can do is to notify your home security company that you will be leaving for a vacation. In that way, if your alarm goes off, they can do something to ensure the safety of your home.