What Battery Is In A Smoke Detector?

9v vs. aa batteries

when it comes to your home and family's safety, it’s critical to have functioning smoke alarms and the proper batteries installed. the battery in your smoke detector should be something that you can rely on.

• 9v has been the battery of choice for smoke alarms for many years.
• however, nowadays, a more common smoke detector battery is two or three aa’s.
• aa batteries have about three times as much energy as a 9v.
• when using batteries like these in your fire detectors, it’s important that you check the detectors consistently and replace your smoke alarm batteries every 6 months.

10-year sealed battery smoke alarm

• in some provinces, it is required to have 10-year sealed battery smoke detectors.
• 10-year sealed battery alarms lasts for the life of the detector, eliminating the need for battery replacements.
• these fire alarms also have an end-of-life warning to remind you to replace the alarm after 10 years.

Smoke alarm batteries

• keep your home and family safe with long-lasting power 9v or specialty batteries for smoke alarms.
• when it comes to something as important as a smoke alarm for your home, make sure you use reliable batteries.
• duracell 9 v rechargeable batteries, 9 v 170 mah
• holds charge for up to 12 months when not in use*
• *retain up to 80 percent of their charge after 12 months when not in use
• duracell specialty 2032 lithium coin battery 3v

Smoke detector battery replacement

the smoke detector takes one panasonic cr-123a lithium 3v battery and has a life expectancy between 3-5 years depending on usage.

1. to change your smoke detector battery, twist it off its bracket and open the back panel.
2. then, replace the lithium battery and put the device back in place.

Power requirements

smoke detectors, fire alarms, co detectors and similar safety products have unique power requirements. batteries for these devices see long idle times with periodic, short periods of high current demand for testing and the need to have power available at any time.

• this type of service requires a battery with a very low self-discharge rate, high voltage and the ability to deliver high current on demand.
• the 9v, pp3 battery is the standard for most manufacturers of these safety products, thanks to its compact size and high power potential.
• while long-life alkaline cells were the optimum choice for many years, today’s lithium 9v batteries meet the needs of this application much more efficiently and are the batteries of choice for most brands.

Four main power sources for fire alarms

there are four main power sources for fire alarms;

• mains powered with a replaceable battery backup
• mains powered with a tamperproof battery backup
• battery powered with a replaceable battery
• battery powered with a sealed in battery.

Mains powered fire alarms

mains powered fire alarms physically connect to your home’s mains power supply, either from the distribution board or a local lighting circuit. this connection must be a permanent mains feed.

• many mains-powered fire alarms operate with a back-up battery source, whether that be a replaceable 9v alkaline battery, or a rechargeable 10-year lithium-ion battery, which would be the more favourable option as it will not need replacing.
• properly test alarms (and, where necessary, replace fire alarms) after, at most, 10 years to ensure adequate protection of your home.
• all of our mains powered alarms have a battery back-up. this battery backup is important to ensure full operation of the alarm in the event of a mains failure.

The benefits of mains powered fire alarms

• british standards will always recommend a hardwired alarm which utilises either a user-replaceable battery, or a tamper proof lithium-ion battery.
• mains powered fire alarms which have battery back-ups are far more reliable than solely hardwired, or solely battery powered.
• they allow for detection for a limited time following the absence of mains power.
• 3000 series) alarms can last up to 6 months with no mains power if without a module fitted, or up to 3 months with the ei3000mrf module.

Battery fire alarms

• 600 series alarms all feature 10-year lithium-ion batteries.
• these are tamperproof and will not need to be changed at any point in the alarm’s lifespan, making them hassle free and easy to use.

The benefits of battery fire alarms

• battery-operated alarms are easy to set up, are smaller and don’t require a call-out for an electrician to install them.
• these alarms also don’t rely on mains power, and the 10-year lithium-ion battery will operate the full life of the alarm, meaning no battery change is needed.

The disadvantages of battery fire alarms

• if an alarm is operated solely with a replaceable battery, the battery will need to be monitored and replaced accordingly when needed as there is no secondary power source.
• there is also the risk of putting faulty or half charged batteries into the alarm which may compromise power levels.
• as a battery depletes, elements of the alarm can work at less than their full capacity and potentially affect sounding, detection, and interconnections with other alarms in the system.

Alarm power type

mains powered with replaceable battery back-up

10 years (5 years for the 140e series)

permanent residencies

continues to operate for a limited time

requires an electrician.

wired or radio-frequency

battery replacement required as well as cleaning and testing the alarm

mains powered with sealed battery back-up

10 years

permanent residencies

continues to operate for a limited time

requires an electrician

wired or radio-frequency

cleaning and testing maintenance only

battery powered with replaceable battery back-up

10 years

smaller homes, short-term lets, quick upgrades

not affected

diy installation

radio-frequency models only

battery replacement required as well as cleaning and testing the alarm

battery powered with sealed battery back-up

10 years

smaller homes, short-term lets, quick upgrades

not affected

diy installation

radio-frequency models only

cleaning and testing maintenance only

Sealed-in 10-year lithium battery

• 600 series, would be a viable option.
• these alarms have a sealed-in 10-year lithium battery, so you won’t need to change the battery at any point during the life of the alarm.
• we would recommend the radio frequency models, so that the system can be interlinked and enable all alarms in the property to sound when one is triggered.