You might want to know the answer to this question, because the safety and welfare of your family can be impacted by how you decide. Battery-source smoke detectors are in widespread use today because they are generally less expensive to buy and less expensive to install, since they don’t require electrical wiring to complete the installation. Good hardwired smoke alarms also have a battery backup, since a power outage renders them useless unless they have a backup battery.
The more relevant question, however, is about you. How reliable are you as a homeowner to keep either type of smoke alarm tested and in working order? It’s smart to change the battery of a battery-source smoke alarm on a scheduled replacement basis. However, waiting until the annoying beep signals a weak battery is the more typical way we keep our home smoke detectors working. If you fall into this category, a hardwired smoke detector may be your best choice. As long as the electric is working, you’re well protected.
Today, almost all municipalities require homes and businesses to have smoke detectors installed, and battery-powered ones are often adequate. Homes built after 1992 can be required, depending on where you live, to have hardwired smoke detectors. Homes built in California after 1992, for example, must have hardwired smoke detectors that also have a battery backup.You can find more information about local code requirements online from your local municipality or by checking with your home insurer. For either type it’s best to choose a good-quality, longer-life battery over an inexpensive one. And post a note to yourself on a calendar to remind you it’s time to replace the smoke alarm batteries. One last thought: Having smoke alarms throughout your house — in bedrooms, garage, basement, etc., — is a good idea.