Battery drain when not in use

I find I am getting about five days worth of a charge too.  I think I am unable to hit the seven days worth of a charge for the same reason you state.  The ISM is still 'on' even when the ISM is not being worn.  In my case I think the ISM still being recognized as being 'on' because the ISM is in a dark room after I take it off.  

I have found that when the ISM is taken off and turned inside out, and the sensor is left in direct light, the ISM seems to turn off quicker than when the sensor is left in the dark.  I have not done extensive testing to prove my theory though.  This is just seat of my pants analysis.

I do agree with you though.  The shortened battery life of five days is frustrating. 

I've found that it seems to sleep when it's been set down and not moved it for a while (It's in a dark drawer, not inside out), as if I go near it after it's been left, it doesn't connect to the connect app.

As soon as I move it, it will connect to the connect app. Sometimes I need to place a finger on the sensor to waken it up. 

I find I'll get around 6-7 days, but there are times when the battery indicator on Connect is randomly all over the place in terms of percentage remaining.

Graeme2812 Are you saying you leave the ISM right-side-in after taking it off?  That you just take it off and leave it be?  Are doing anything different with your phone?  Is your phone still within Bluetooth reach of the ISM after you take it off?

Thank you.

Definitely not getting seven days/nights of use.  At most I get five days.  Right now I am tracking battery drainage each night so I will report back with some numbers in a few days.

The ISM has no vibration settings turn on.

The ISM turned inside out when not in use.

The ISM is not placed on a reflective surface when removed.  The ISM is placed on a bathroom countertop or night table.  When on a night table a light is left on, reflecting down on the exposed sensor.  My thinking is the sensor needs the light to know to turn off.

So my morning routine with the ISM is to take it off and lay it in a drawer (so a still and dark place) with the rear of the module side down. And that’s it.

I’ll open my phone and assuming I’ve still got Bluetooth on, it’ll connect almost instantly and synchronise. It takes maybe 60-90 to sync and that’s it.

If I move <my phone> away from the ISM and go back later, assuming the ISM hasn’t bee moved, it won’t automatically re-connect. It is as if the ISM is in a sleep state. 

As soon as I pick the ISM up, or hold a finger over the sensor for a few seconds it gives three short vibrations and it reconnects (awakens) again. 

Thanks Graeme2812 . Sounds similar to what I do, except that I leave the ISM face up and either in a dark room after I leave the room or if I can, I will leave the ISM turned inside out and under a light.

I am tracking battery usage to see if any of the things I am doing can extend or impact battery life.

I have to say that the battery drain catches me out sometimes. It doesn’t seem entirely accurate all of the time. e.g when it’s LED status shows full, Connect reports 98%/99% etc. or I’ll check and see around 30% then, the next day it’s showing 10%.

That all said, I’m still pleased Garmin released this and am happy overall with the ISM. 

I did some random logging of battery state in the morging and the evening.

The morning value was determined after removing the ISM, and the evening value was determined immediately after putting on the ISM.

Throughout the day, the ISM lies next to the bed with the inside facing out and the sensor facing up, and is not moved or anything.

I'm really wondering why the ISM consumes an average of 14% over the course of a day when not in use. My Forerunner is more economical...

Well, thanks for that answer, but it does not answer the question why the battery use over the day when the ISM is not used and lies around is that high.