how does the backup battery for an alarm system work (3)

How Does the Backup Battery for an Alarm System Work?

The backup battery for an alarm system works by slowly storing power while the panel is running on AC power. 

Once AC power is lost, the battery will activate to keep the system running. A backup battery can only power a system temporarily. It is a short-term fix until AC power is restored.

Keeping an alarm system powered on at all times is very important. When a system is powered off, monitoring service cannot be provided, and the home or business is left unprotected. 

That is why security systems have backup batteries to ensure that they always remain powered on. The shape and size of the backup battery will typically depend upon the alarm panel used. 

Wireless all-in-one panels will usually have a small battery pack that plugs into the main system board. 

Wired panels use larger batteries that look like miniature car batteries. Despite their size, they can still be secured inside the same metal enclosure as the panel. 

But in any case, the primary purpose of the battery is the same.It's designed to keep a system and its accessories working correctly when the power is out.

When a system runs on the AC power provided from its plug-in transformer, its backup battery slowly stores a small amount of energy. 

This way, it will be ready to activate when AC power is lost. This can be due to an electrical outage, or it could be because the transformer was unplugged or disconnected. 

The panel will display an AC loss condition so that you are aware that AC power was lost. The system will remain on backup power for as long as the battery can keep the system powered on. 

Most batteries can keep a system running for between four (4) and 24 hours. Refer to the specifications for the panel and the battery you are using for an estimated duration of power time. 

Keep in mind that a battery can only provide temporary power. A system should use AC power whenever possible.

One important thing to consider when using a backup battery for an alarm system is that it will also keep the system's communicator running. 

This is what allows the system to connect with a cellular and internet network for service. 

If the communicator goes offline, then the monitoring service will be lost, so keeping this piece of equipment running is very important. 

But if you are using internet-only monitoring, your modem and router must also be supported online for your panel to maintain connectivity. 

If this equipment does not have its battery backup, then a power outage will take it offline, and your system will be left unmonitored, even if its internet communicator remains active. 

That is why many users will invest in cellular communicators for security systems. Cellular communicators speak with cell towers, which are unaffected by regular power outages. 

In addition, cellular connectivity is more reliable, and it is much less susceptible to random outages like internet connectivity. 

Overall, a cellular communicator represents the best way to keep a system monitored during a power outage. 

Just keep in mind that you will need a monitoring plan that includes cellular connectivity if you want to set up a cellular monitoring service for your system.

Common Symptoms Of A Bad Backup Battery

how does the backup battery for an alarm system work (2)

If your alarm system’s backup battery is entirely dead or goes wrong, you may experience some of the following symptoms:

  • The alarm goes off when power is lost and restored, such as during an electrical storm.
  • You have to reset your alarm system’s time/date anytime the power is lost and restored to clear the trouble light or icon.
  • Keypads do not work while power is out.
  • The trouble light is on.
  • The system does not work for at least 8 hours (or as long as your system should last) when using battery power only.

Depending on your particular alarm system, you may also have wireless sensors that require batteries as well, so it may not be clear exactly which battery needs to be replaced.

Alarm System Backup Battery Replacement – Information

If you have a hard-wired or hybrid (wired and wireless) system, then you should have a metal security box or cabinet enclosure that contains a rectangular battery. 

This battery is vital to the system's operation as it is used to keep the system powered up and working for several hours in the event of a power failure. 

If this battery goes terrible or stops recharging, you will likely experience some of the symptoms of a bad battery described above.

Locate The Metal Security Box Or Cabinet Enclosure With A Backup Battery Inside

The alarm panel box is usually located in an MBR closet, hallway closet or utility room but could be anywhere. 

While not common, we have also found them inside bathrooms and attics, so be sure to look everywhere.

Open The Metal Security Box Or Cabinet.

Once you have found the box, you may need to have a key or use a screwdriver to remove the cover. TIP: Sometimes, the key is sitting on top of the box.

Locate The Backup Battery

Inside this box, you should find a black rectangular battery along with a lot of wires and a circuit board. 

The main circuit board is the brains of your system and contains all programming information. Some of the wires go to each of your keypads, door sensors, window sensors, motion/glass break detectors, siren, phone line, cellular radios, etc. Be careful not to touch anything unless you have a reason to.

How To Replace A Security System Backup Battery

Every security system needs a backup battery. This item is required in case of an emergency, such as a power outage. The backup battery may only power your alarm for up to 8 hours. 

However, this can be crucial to your peace of mind and safety. Since security system batteries last for years, you don’t have to switch them out very often. 

When it’s time to replace them with new batteries, you will notice a blinking “low battery” icon on your alarm pad. 

First, put your security system in test mode and make sure the power is off. Then, switch the batteries. Finally, turn the power back on and remove your security system from test mode.

Put Your Security System In Test Mode And Make Sure The Power Is Off.

Before you crack open your security system, you will need to contact your alarm monitoring company. 

While you work on your security system, it needs to be in “test” mode. If the alarm goes off while operating in test mode, the company will know you are not really in danger. 

This process will ensure that the alarm company won’t send anyone out to check on the situation.

Make sure to power down the security system before you work to avoid any injury. Disconnect the transformer or flip the circuit breaker switch to ensure power is off while replacing the old battery with a new one.

Switch The Batteries

Use the right tools to open up your system’s control panel to access the battery. This may require either a screwdriver or a control panel key that unlocks the board. You will see the battery, as well as a black lead and a red lead. Carefully disconnect these leads to remove the security system battery.

Remove the old battery, and replace it with the new battery. Insert the plugs into the correctly coloured leads, and replace the control panel case.

Turn The Power Back On And Remove Your Security System From Test Mode.

Power up your security system by plugging everything back in or flipping the circuits back to the “on” position. 

Your “low battery” light should flicker off, and now you can call your alarm company back and alert them to remove your system from its “test” mode since you have replaced the old battery with a fresh one. It would be best if you didn’t have to change out your battery more often than every three years, though backup batteries can last as long as five years.

Getting a replacement Backup Battery

Most Alarm Panels require (1) 12V Sealed Lead Acid battery rated @ 4, 5, 7 or 8 Amp Hours. 

The size of the battery depends upon your specific panel and the electrical requirements of the sensors and equipment you have installed on your system.

It is vital to replace with the same size battery or use an acceptable replacement for your system. Our 12V batteries range between $30 and $50, depending on the rated Amp Hours needed and warranty. 

Unfortunately, these batteries are not sold at Walmart, Target, Home Depot, Lowes, etc. One local DFW store we are aware of is: Batteries Plus Bulbs (example battery for an ADEMCO P801 system)

If you do not feel comfortable with or can safely replace your battery or would rather have a professional do it, we offer a Professional Battery Replacement Service using your battery or our own.

Before Attempting To Replace The Battery Yourself

how does the backup battery for an alarm system work

Put your system into test mode to prevent any possible false alarms and dispatch emergency response services.

You will need to provide your account CS # and spoken codeword via one of the following methods:

  • 24/7 Alarm Response Center
  • Customer Care
  • By Text: Send “Please put my system to the test for 2 hours.”
  • Online Chat: Send “Please put my system to the test for 2 hours.”

Self-monitored systems – Ensure you know how to disarm your system.

Make sure you can safely remove your battery without inadvertently tugging on or pulling any wires loose.

It would be best if you disconnected the power to the alarm system to prevent any possible shorts unless you are experienced. You can detach the power by using one of the following methods:

  • Unplugging the alarm system’s transformer: The transformer is usually a white or grey coloured 3″x4″ plastic 16.5V 10-40VAC wall wart but may be black or painted a different colour. Off. The device will be plugged into an outlet within the home, usually in the same area as the MBR closet, laundry room, utility closet, but maybe in the attic, garage (ceiling or on wall plugged-in) or elsewhere, so be sure to check all wardrobes and rooms. Tip: Bring screwdrivers. They are usually attached to the outlet with a flat or Phillips head screw.
  • Turning off the circuit breaker to the alarm system: Unless you know for sure which circuit breaker goes to the alarm system and has been verified, you may need to have someone help you figure out which one is for the alarm system by turning off the breakers one by one.
  • You were shorting out one of the wires accidentally! That’s right, and if you touch power wires inside the panel to ground, you will likely be needing a new transformer at a minimum! So be careful when working on your battery, as you could end up shorting out components on your system.

Please make a note of where wires and their colours are attached to the battery. It’s always a good idea to take a few pictures.

Disconnect wires connected to old batteries, install new batteries and attach wires to new batteries. Tip: Usually, it’s battery (+) to a red (+) cable and battery (-) to a black (-) thread. Be very careful as an incorrect connection could damage your equipment and cause sparks to fly!

After re-connecting cables, plug back in the transformer or turn back on the circuit breaker. Your system should now be up and running again. Check the keypad for any trouble conditions.

The time/date will likely need to be set to clear a time/date, not set in the trouble condition that usually appears after losing both AC and battery power.

You may need to clear any other error messages or trouble conditions on the alarm keypad due to losing both AC and battery power.

How To Test And Replace The Backup Battery In An Alarm System

The backup battery in a residential alarm panel provides power in case of an outage. It is located in the main panel box for the system and is a sealed lead-acid type, most commonly 12 volts. Check your battery regularly and install a replacement if necessary.

Step 1

If your system is monitored by a central station, be sure to call and put the system on "Test" to avoid police dispatch.

Step 2

Locate the alarm panel box (NOT the keypad used to enter your code). The battery will be inside.

Step 3

Open the lid. Most lids are held with screws; if it has a lock, look for the key on top of the box or in a "catch-all" drawer in the kitchen. If you can't find the key, call an alarm professional.

Step 4

Find the battery, usually at the bottom of the panel box. Note the voltage printed on it. The most common is 12 volts. Also, notice if there is a date written on it. If it's more than five years old, it should be replaced - see Step 8.

Step 5

Using a voltmeter set to "DC Volts", connect the red probe to the red terminal and the black probe to the black terminal. The meter will read a little over 13 volts (for a 12-volt battery).

Step 6

Locate the AC transformer. This is a 2- to 3-inch cube-shaped unit that plugs into an outlet, often near the alarm panel box or the garage door opener outlet in the ceiling.

Step 7

Unplug the transformer, and watch the voltage on the meter. If it drops slowly for several minutes, then settles around 12.5 volts or higher (for a 12-volt cell), then the battery is good. If it drops below 12.5 volts (for a 12-volt unit), then it isn't good.

Step 8

If the battery is good, plug in the transformer and close up the panel to finish. If it's terrible, plug in the transformer so the alarm will have power until you get a replacement. Remove the leads from the battery terminals by pulling straight back on the connector toward the wire. Take the unit to a supplier to purchase a replacement battery.

Step 9

Install the new battery. Connect the red lead to the red terminal and black information to the black terminal. Write the date on the new unit with a felt-tip or ink on a piece of tape.

Another thing to remember about backup batteries is that they will eventually lose their ability to store a charge. 

This usually happens after about three (3) to five (5) years of use, though it can vary depending upon the model. 

Once a battery is no longer able to store an adequate charge, the system will display a low-battery warning message. 

This is the same warning that you will get if no battery is detected by the system or if the battery has been allowed to drain too much without recharge while the system is running on AC power. 

If you encounter a low-battery trouble condition on your system, try giving the battery 24 hours to recharge while the system is running on AC power. 

Make sure that AC power is not lost or disturbed during this time. Then try to clear the trouble condition by following the steps appropriate for your panel. 

If you cannot remove the low-battery message, or if your system displays low battery then restores when there has been no AC loss condition, then it is likely that you need a replacement. Make sure to purchase an appropriate battery for your system.

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