Can't connect my HRM-run to my Fenix 5 Plus

Reversing battery is not really possible if you look how it is constructed.  negative is on one side while the positive is on the other sides and the side walls.  So when you revert the battery you are actually connecting positive to both connectors.  Nothing happens.  No charge floats one or other direction.

Reversing battery is not really possible if you look how it is constructed.  negative is on one side while the positive is on the other sides and the side walls.  So when you revert the battery you are actually connecting positive to both connectors.  Nothing happens.  No charge floats one or other direction.

My HRM run refused to work after 1 1/2 years and if you look at Amazon comments, this seems to be the "normal" lifetime. Luckily in Europe we have 2 years warranty and Garmin replaced mine without any issue.

The principle of "reversing" the battery is to use the battery to short the terminals so no charge remains in the circuitry.  It is not to connect power in reverse polarity as that would probably damage it.

I had exactly the same issue being unable to connect my Garmin HR start to my FENIX 5. Tried all the usual tricks but the clincher was reversing the batter in the compartment. Now it works as it should. Good job, many thanks for that!!

Another +1 for this successful solution. Consistent with the nerdiness of Garmin products!