Garmin InReach Explorer+ Battery Life

Since the battery in the Garmin InReach Explorer+ can not be replaced by a Garmin user, and can not be replaced by Garmin Support, what is the life span of the Lithium ion Battery in the Garmin InReach Explorer+ ??  I have found the life span for my lIBM laptop rechargeable Lithium ion battery is 2 to 3 years, regardless of how many times I recharge my laptop battery.  This is an important question because the life span of the Litihium Battery in the Garmin will determine the life span of the Garmin InReach Explorer+.. For my laptop battery, the life span of my battery starts after the time of manufacture, not the first time the battery is used, so the manufacture time stamp is important.  This is an important question for me, because I am concerned about depending on my Garmin on an extended sailing trip of several weeks, or several months, where replacing my Garmin would be difficult, if not impossible.

Thanks,

Jim