Don't know about an O2 alarm
But a CO/LP Detector will 'chirp' due to low battery voltage
When they detect they beep continuously and have to be reset
Is it time for your medication or mine?
2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31