Current battery percentage show in mobile app?

Really?
It is easiest for you to check your watch battery level on the mobile not on the watch?
Especially that you can set up your watch face constantly presenting such information.

Easiest is to grab a phone, open app and check battery level on you watch, instead on just look on watch face and see battery level on it. 

iAs you say so. 

While charging it's easier to check the phone than the watch in the other room. Moreover, I don't have this information on my watch face, as there are limited data fields you can present. So it makes absolutely sense to have that info in app. And it is super easy to have it in the app.

During charge, agree.
Rest, again doesn't make sense.
Just press down button to open widgates and you have battery percentage on the top.

To be clear, I talk about Fenix/Epix family.

I’d take during charge!

vpier said:

And it is super easy to have it in the app.

If you mean that it is super easy for Garmin to add it, then not really, because it is not enough to change the app. The battery info is currently not in the standard data set being transmitted from the devices to the app live. It means Garmin would have to change the firmware of all their models, which of course, is a rather costly operation. Still, you can try suggesting it to Garmin at Share Ideas | Garmin - if they see it is a massively demanded feature, they may consider adding it (at least at new models).  

I don't know the exact electronic logistics of Garmin's firmware rollouts, but if we can change settings and data screen in the app, we should be able to see current battery level in the app, too.  My $100 Amazfit and app can do it, and I know other platforms have that same device-app communication.  I have submitted on the Share Ideas page too.

revcph said:

I don't know the exact electronic logistics of Garmin's firmware rollouts, but if we can change settings and data screen in the app, we should be able to see current battery level in the app, too.

Only very limited set of data is currently being transferred to the phone app from the watch live - the HR, Steps, Calories, Floors, and Intensity Minutes. The majority of other data fields are currently simply not available to the app, so the app cannot display them. Most of the other metrics is being synced only occasionally a few times a day.

Technically, it is of course possible to share more data with the app live, including the battery level, but that requires a modification of the firmware of each watch model, hence this feature is not something that could be added quickly and simply.

A possible workaround is using a 3rd party Connect IQ app that would broadcast the information to a separate compagnon app, but it cannot communicate it directly to Garmin Connect (with the exception of Activities, which would not be much helpful in this case).