If the InReach is off and you need to send an SOS you’re hosed.
If the InReach is off and you do manage to send an SOS you’re hosed because the SOS center doesn’t really know where you are.
Your family is not your primary rescue information center.
Take the InReach back to REI. Ask them to set it up for minimum position transmission, 10 minuets I think, and maximum battery time. Turn it on at the trailhead. Leave it on.
Send the preset text messages as needed. Tell the family there’s no need for reply chit chat UNLESS they get an OH YUCK! I’m hurt message after you send the official SOS message.
If you still think that you’re using the battery excessively trade your dozen phone batteries for a single 10k MAH battery that will charge the phone and the InReach.
InReach ON, phone on in Airplane Mode while on the trail.
You can check the InReach for battery drain at home by turning it on, stick it in a pocket and go about your daily routine including any training hiking, shopping, grandkids cooking, etc.
That’s All Folks!
Wayne