I'm coming from a Pebble which had GREAT battery life (comparatively speaking). Then I picked up the Gear S2 4G and the watch barely made 8 hours with very average use. Then, fiddling with the settings, I found SETTINGS --> CONNECTIONS --> MOBILE NETWORKS -->GEAR NETWORKS --> AUTO SWITCH (X). I turned this feature on and WOW what a difference. I unplugged my watch at 5:30 AM yesterday and at 9:00 PM it was at 50%. I unplugged today at 8:00 AM and it's 3:30 PM and it's still at 70%. Much better!