Alarm Panel Battery

Monk · Jan 20, 2009

Another post here brought to mind something I consider every so often. I am attempting to make this work by a "Poll" function. Hope it comes out right.
Many here I believe possess an above average level of knowledge regarding security systems and electronics. I am curious to know what is your perception - a best guess with no case studies, testing or anything else - of how long an alarm backup battery will keep a panel powered sufficient to sound an alarm and be able to report trouble to the monitoring service.
For fun, lets say the system is an Elk M1G with 2 zone expanders, a wireless expander and 3 keypads.

dutchyn · Jan 20, 2009

Monk said:
For fun, lets say the system is an Elk M1G with 2 zone expanders, a wireless expander and 3 keypads.

Are you going to specify the battery as well: I suspect that the most common is 1280 (8 Ah) because it comes with most of the kits, but there is a 20-fold range, from 1.3 Ah to 26 Ah.

Monk · Jan 20, 2009

ChrisDutchyn said:
Monk said:

For fun, lets say the system is an Elk M1G with 2 zone expanders, a wireless expander and 3 keypads.

Click to expand...

Are you going to specify the battery as well: I suspect that the most common is 1280 (8 Ah) because it comes with most of the kits, but there is a 20-fold range, from 1.3 Ah to 26 Ah.

Sure, why not... I haven't looked @ my battery but I'll bet you are right. It's the one that shipped with the M1 and is "Elk" branded.

icellama21 · Jan 20, 2009

If I remember correctly the M1G requires at least 16AH to meet the NFPA 72 requirements for 24 hours + 5, so I don't think the 8AH is going to last very long ....

Lagerhead · Jan 20, 2009

My system (very similar to the specified configuration) will run for at least 12 hours, because it happened just last week after an ice storm. 8Ah battery that comes with M1SYS4 package.

Monk · Jan 20, 2009

Lagerhead said:
My system (very similar to the specified configuration) will run for at least 12 hours, because it happened just last week after an ice storm. 8Ah battery that comes with M1SYS4 package.

Just checked - mine is indeed an 8Ah battery... Had no idea it would go for 8 hours. I did notice there was a provision for the (Elk) alarm to shut itself down on low voltage... Wonder if it reports that before it does shut down.

WayneW · Jan 20, 2009

Elk makes this pretty easy to determine for your system. the keypad will show the current being used by your system at any time. For most people, this will remain pretty constant, hour over hour, excluding alarm conditions. Simply take the amount of battery you have (in AH amp hours, the default is 8 AH for the single battery) and divide by your current usage. So, if you have an 8 AH battery and use 1 A in non alarm conditions, then (assumed your battery is not old & worn out), you should have 8 hours of battery life. If you use .5A (500ma), then you would have 16 hours of battery life.

You will also want to keep in mind the current and battery sizes of your auxiliary power supplies (if you use them) because if the aux battery dies before the main battery, you don't want to generate false alarms from dying sensors or missing expanders, etc.

Lagerhead · Jan 20, 2009

Monk said:
Just checked - mine is indeed an 8Ah battery... Had no idea it would go for 8 hours. I did notice there was a provision for the (Elk) alarm to shut itself down on low voltage... Wonder if it reports that before it does shut down.

[a] Yes I was getting low battery warnings just before power was restored; my normal system draw is around 500 mA as reported by the M1 itself (86 System Diagnostics, 2 System Volt/Current).

Monk · Jan 20, 2009

WayneW said:
Elk makes this pretty easy to determine for your system. the keypad will show the current being used by your system at any time. For most people, this will remain pretty constant, hour over hour, excluding alarm conditions. Simply take the amount of battery you have (in AH amp hours, the default is 8 AH for the single battery) and divide by your current usage. So, if you have an 8 AH battery and use 1 A in non alarm conditions, then (assumed your battery is not old & worn out), you should have 8 hours of battery life. If you use .5A (500ma), then you would have 16 hours of battery life.

You will also want to keep in mind the current and battery sizes of your auxiliary power supplies (if you use them) because if the aux battery dies before the main battery, you don't want to generate false alarms from dying sensors or missing expanders, etc.

I was able to get to the settings that showed me 14V and .5 amps (fluctuates a small amount) - So is this to say that if I doubled the Ah size / rating of my battery, I would double my "run time"? Giving me maybe 32 hours? Sounds like something to consider doing.

Of course this tech talk has poisoned the poll!!

My first thought was 8-16 hours...

WayneW · Jan 20, 2009

Monk said:
I was able to get to the settings that showed me 14V and .5 amps (fluctuates a small amount) - So is this to say that if I doubled the Ah size / rating of my battery, I would double my "run time"? Giving me maybe 32 hours? Sounds like something to consider doing.

Yup, doubling your battery would double your runtime. The battery folks always suggest replacing sets at the same time, so I would be nervous about adding one new battery to one old battery. But upgrading one old battery to two new batteries is easy. The best way to do this is to get piggyback crimp terminals on the primary battery so you can connect the second battery in parallel. I got my piggyback terminals at an appliance parts shop. Do NOT connect the two batteries in series and give your control a 24volt heart attack.

Digger · Jan 20, 2009

icellama21 said:
If I remember correctly the M1G requires at least 16AH to meet the NFPA 72 requirements for 24 hours + 5, so I don't think the 8AH is going to last very long ....

The UL rating for Residential Fire on the M1 is 500 ma standby power for 24 hours and requires 2 of the ELK-1280. That gives you 5 minutes of alarm (for Canada as the US only requires 4).

I currently (pun intended) have a 800 ma load on my panel so I ordered a 26 Ah battery until I can shed more of the load and do it correctly. Technically that is beyond what Elk recommends can be properly recharged by the panel (max 18 Ah if I believe) since if I remember correctly the max charge current is about 500 ma but it drops off as the battery charges. NFPA only gives you 48 hours to refresh your batteries.

I also have 3 aux power supplies with their own batteries to power the additional loads (all total about 2.5 A).

Most of the "free" or $99 specials you get from the alarm installers give you a 4 Ah battery that really does not provide much power. If you have a 7 Ah you would still need to derate to about 120 to 150 ma to get the 24 hours plus alarm current (which would be very low).

Digger · Jan 20, 2009

Lagerhead said:
Monk said:

Just checked - mine is indeed an 8Ah battery... Had no idea it would go for 8 hours. I did notice there was a provision for the (Elk) alarm to shut itself down on low voltage... Wonder if it reports that before it does shut down.

Click to expand...

[a] Yes I was getting low battery warnings just before power was restored; my normal system draw is around 500 mA as reported by the M1 itself (86 System Diagnostics, 2 System Volt/Current).

The M1 reports low battery at 11.2 V if I remember correctly. It should operate down to 10.2 before it shuts down to save the battery.

Monk · Jan 21, 2009

WayneW said:
Monk said:

I was able to get to the settings that showed me 14V and .5 amps (fluctuates a small amount) - So is this to say that if I doubled the Ah size / rating of my battery, I would double my "run time"? Giving me maybe 32 hours? Sounds like something to consider doing.

Click to expand...

Yup, doubling your battery would double your runtime. The battery folks always suggest replacing sets at the same time, so I would be nervous about adding one new battery to one old battery. But upgrading one old battery to two new batteries is easy.

whoops - sorry, I was misunderstood - what I was asking was to double the Ah capacity not add a second battery. I now see that you can only go so far with larger Ah ratings before the physical battery size would no longer fit... (In my current config I have the battery with the Elk in a small can.) Thanks for taking the time to reply!

ASIHome · Jan 21, 2009

You also have to make sure that the charging circuit on the Elk M1G can handle the amount of battery you put on there, otherwise they won't charge properly. I do not know what the Elk M1G spec is but on an HAI the charging circuit can only handle 16Ah.

WayneW · Jan 21, 2009

Monk said:
whoops - sorry, I was misunderstood - what I was asking was to double the Ah capacity not add a second battery. I now see that you can only go so far with larger Ah ratings before the physical battery size would no longer fit... (In my current config I have the battery with the Elk in a small can.) Thanks for taking the time to reply!

Yes, you can upgrade your runtime via two means (depending upon your physical space). You can add a second identical battery or you can upgrade to a larger battery (doesn't have to be exactly double)

Alarm Panel Battery

Monk

Active Member

dutchyn

Active Member

Monk

Active Member

icellama21

Active Member

Lagerhead

Active Member

Monk

Active Member

WayneW

Senior Member

Lagerhead

Active Member

Monk

Active Member

WayneW

Senior Member

Digger

Senior Member

Digger

Senior Member

Monk

Active Member

ASIHome

Active Member

WayneW

Senior Member

Similar threads