Can I use my Onelink Environment Monitor on Battery only?

The Onelink Enviroment Monitor with battery backup is designed to provide backup emergency power in the event of AC power outage and is not intended to operate the alarm for extended periods of time.
The battery back-up is designed to provide emergency power to the CO Alarm for 7 days. Actual back-up time depends on the strength (freshness) of the battery. The battery back-up will not work unless a good battery is properly installed.