Bettery life with this settings

A lot depends on the circumstances. Anything which uses a radio - BT, ANT, GPS or Iridium modem - will negatively impact battery life. 

Although I do not know for sure, BT and ANT radios are likely to run continuously if enabled. This is because the “remote control” use case requires more or less continuous communication between the Mini and the phone or watch.

With no sent or logged track points, the GPS radio will remain off unless you do something which requires a fix. Things like check your position, mark a waypoint, send a message, and so forth. Would not be surprised if a mail check (see below) also requires a fix.

The Iridium radio will also remain off unless you do something which uses it. Things like sending a message or asking for a manual mail check. The big exception is automatic mail checks. The unit checks on power up and at one hour intervals. AFAIK, that cannot be disabled directly. With a good sky view, the check is not inordinately expensive. However, in challenging conditions, the unit will try VERY hard to complete the check. It will retry for a long time. This can result in unexpectedly heavy battery use.

The manual says that extended tracking disables the message check. I have no personal experience with that but I have no reason to believe it’s not true.

With your initial assumptions including no BT, I would expect you to get something approaching the promised  battery life in extended tracking mode with 30 minute send interval - up to 24 days as explained here:  https://www8.garmin.com/manuals/webhelp/inreachmini/EN-US/GUID-26D02F01-8090-4D52-B466-D93B670E898F.html. That assumes you are careful to avoid extended retry with your mail checks. Extended tracking with manual mail checks is probably the optimal thing for your scenario.

Dear Twolpert:

Thanks for your answer. I don´t know why ,

but I forgot that in hard environment the unit will make an effort to take signal.

This will drain the battery.

Extended trackinng could be an option ,but I prefer to leave the unit off ,and when (in the middle of trekking) stops to rest,or lauch , will tur it on and check via Bluetooth on , with the smart phone kayboard also.

So thank you very much for your suggestion

Dear user

For me is not trouble to let it on my backyard a full day .

However (as Twolpert said and I forgot to think ) , the problem will be, that doing this simulation , will be not a hard environment as a deep wood or canyon must be.

So the result is not going to be very accurate .

I decided to turn it on and send/check message each time I stop to launch or rest or take a photo .

For me , is my best setting .This covers my needs

Thanks Martin

Any case it will be interesting to perform this test on your backyard especially if you not need device for regular tracking / messaging. 

Yes , maybe I perform it.I will try to simulate a haerd condition and see what happens.Keep you posted Tks