This discussion has been locked.

You can no longer post new replies to this discussion. If you have a question you can start a new discussion

UltraTrac availability, possibilites and battery life?

Former Member over 7 years ago

I'm getting mixed information regarding UltraTrac on the FR645. Ray at DC Rainmaker does not mention an UltraTrac mode in his in depth review (https://www.dcrainmaker.com/2018/03/garmin-forerunner-645-music-gps-watch-in-depth-review.html#product-comparison) as he does with the other watches.
The product information page (https://buy.garmin.com/en-US/US/p/591311) only states "14 hours in GPS mode" and no mention of UltraTrac (for reference, the FR935 page states "up to 50 hours in UltraTrac

mode (with wrist-based heart rate), or up to 60 hours in UltraTrac

mode (without wrist-based heart rate)").
However the manual for the FR645 describes how to change the preferences of an activity to enable UltraTrac...

Are there any FR645 owners here who have tried UltraTrac (if available) and if so, did you measure/estimate the change in battery life? And also: can you change GPS mode to UltraTrac for any activitiy type?

0 skopek over 7 years ago

Yes, I tried it with a hike activity based on walk.
No I haven't really checked the battery drain during the 90min.
Yes you can change it in any activity.

You have way less GPS updates!

0 chunkywizard over 7 years ago

On the 645 you can change the GPS mode to Ultratrac on both Run and Bike activities (they are the only 2 I checked). I haven't used it, but it's there

CW

0 ares952 over 7 years ago

I am in the battery life in ultratrac mode interested too for FR645.
When I compare it with FR935:
7days in smartwatch vs. 16days in smartwatch
12 hours in GPS mode vs 24 hours in GPS mode
?? hours in ultratrac vs 60hours in ultratrac

I would say, that in ultratrac it will last for approx 30 hours but I would appreciate the confirmation.

0 emr215 over 7 years ago

I have a slightly different, but related question. In the app setting (run/walk/bike etc..) you can turn Ultratrac on in the GPS section, and in the watch setting you can set Data Record to either smart or every second. What exactly does Ultratrac do and how does that differ from Data Record setting?

0 R_Tellis over 7 years ago

The data recording rate is simply a way to manage how often the watch records to the FIT file. With 1 second recording all of the relevant data gets written to file every second, while smart records less frequently about every 5-7 seconds. It was really just a way to keep file sizes down when memory was more expensive and data transfer for wearable devices was much slower and has no impact on battery life or accuracy.

Ultratrac differs from regular GPS in that it only turns the GPS radio on for 20 seconds out of every minute to make sure it knows where it is and does a sort of dead reckoning for the time in between using the accelerometers, compass, and gyroscope built in to the watch. Less accurate but saves battery.

0 emr215 over 7 years ago

Makes perfect sense. Thanks for the clarification.