Assertion: detector | /r/CapableOf | use battery
Facets:
value: to provide backup power
type: PURPOSE
Source sentences:
text: Secondly, if your detector uses batteries, you need to confirm that it has batteries with relatively long lifespan.
text: Detectors that are hard-wired to the home’s electrical system use this battery to provide backup power in case a fire knocks out the house’s electrical power.