GPS modes and battery drain

I have a 5s plus. My battery life is decent when in normal usage, but gets completely drained whenever I use GPS.
I tested all different modes, GPS only, Galileo, Glonass, Ultra tac. It does not seem to make any difference. Basically it is down to 4-5 hours, and I do not use music, as it is mainly ocean surfing-swimming.
I just wrote to Garmin support.

I read some of the pages in the battery thread, but I was wondering if people with no battery issues see any difference in battery drain changing the GPS modes.
Do you have any suggestions?

0 Dr Phil over 6 years ago

I'm sure you are aware there are many factors that affect battery performance. The manual for the 5S+ suggests up to 11 hours for GPS with wrist HR. You'd expect less if you connect to external HR and perhaps have BT on. That said 4-5 hours is a bit light. Have you actually checked the battery life when in use? Is the 4-5 hours a projection based on a an activity? I was getting around 8h with BT, connection to external HR, 1s recording and GPS only. I thought that was reasonable. However, with that and the normal use, the battery life was a bit low for my needs so I swapped out for a 5+.