Do you really have to replace your smoke alarm batteries?
November 3, 2017
“Change your clock, change your batteries.”
Fire safety officials and the Energizer Bunny have been working hard to drum it into us (no pun intended) for years: whether you rent or own, when daylight saving time ends and you turn back the clocks, it’s also a good time to put new batteries in your smoke alarms.
Yep, every year, they insist, even if the old ones still have some life in them. And even if you have hardwired alarms, you want that battery back-up in case of a power failure.
Sounds like overkill, right? How often do all those alarm batteries really need changing? Why not wait until they actually die? The thought of landfilling a pile of batteries every year hurts even more than the cost of replacing them.
The thing is, this annual safety campaign isn’t just about selling batteries. Smoke alarms draw a very low amount of power — until they go off. Then, to be loud, they need a good strong supply. If your home is on fire in the middle of the night, you want those alarms to SCREAM at you. Working batteries that aren’t fresh might not have enough juice to get the job done.
It’s an easy case of better safe than sorry.
Almost two-thirds of home fire deaths happen in homes where the smoke alarms aren’t working, or that don’t have smoke alarms at all, according to the National Fire Protection Association. Your risk of dying in a home fire is cut in half when you have working smoke alarms. (Carbon monoxide is also incredibly deadly; many smoke alarms also detect CO, but confirm that yours does.) So let's change those batteries!
Here are some tips that will help with the task and keep you and your family safe.
Pry before you buy
Most smoke alarms use 9-volt alkaline batteries, but some use AA. So if this is the first time you’ve replaced yours, do open the battery compartments on your units and check before heading to the store. You wouldn’t want to waste that extra hour.
Save the rechargeables for the remote
Green points for thinking of it, but alarm manufacturers do not recommend using rechargeable batteries because they tend to lose their charge faster.
Skip the lithium batteries
Here's another idea that sounds good in theory, but isn’t. While 9-volt lithium batteries last longer than alkaline batteries, when they die, they die fast, says Consumer Reports. That means you’ll have less warning that they’ve gotten weak (your alarms should chirp if the batteries get low).
Go with a brand name
Why take the risk of using an off-brand just to save a few bucks?
There’s one way around this annual chore
There is an exception to the every-year rule. Some newer smoke alarms have a sealed lithium power supply that lasts the life of the alarm, 10 years. If your alarms have no visible battery compartment, this must be what you have. These alarms are about twice as expensive but will probably pay for themselves in batteries.
Is it time to replace the alarm itself?
The date it was manufactured should be on the back. Heat and smoke sensors get less sensitive as they age, so if it’s 10 years old, replace it.
Dispose of old batteries properly
Batteries often contain toxic metals, sometimes mercury. Some states don’t allow any type of battery to be thrown in the trash, so check your city or state’s rules.
Plus, used batteries often aren’t 100 percent dead yet. They can potentially be shorted by contact with each other or other metal objects, and then leak, overheat, or rupture. The super-safe thing to do, especially with 9-volt batteries, is to cover the contacts with masking, duct, or electrical tape.
Test your alarms monthly
Most people don’t, even though it’s incredibly easy: just push the test button. After all, things happen. You could get a dud battery, or it could get drawn down fast for some weird electrical reason. We recommend putting a monthly reminder in your home maintenance calendar. When you test, vacuum off dust too, to help prevent false alarms.
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Filed Under: For Homeowners