Garmin Fenix 6s Battery Life

I have the Fenix 5s and the battery does not last an entire Ironman without charging it during the race, even after shutting off most features. I have a small wrist and the size of the watch is perfect. I am due for a new one and looking at the Fenix 6s or Fenix Pro (next size up). Does anyone have experience with the 6s lasting a 12-13 hour Ironman/Ultrarun?

Thanks!

I have a 6X Pro and it used up 9% battery life on a 2:20 run with backlight set at 10%. Battery life is significantly less at high backlight settings.

The 5s is quoted to last 14hrs in GPS mode, the 6s improved to 25hrs GPS mode.

So, yes the 6s should last a full IM quite comfortably.

https://www.wareable.com/garmin/garmin-fenix-6s-review-7782