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Will the Battery Life improve or is this it?

Markus
over 2 years ago

Hey,

Do you think any future update will solve the bad battery life of this watch when LTE is enabled? 

I never even got close to half of the promised LTE battery life.

Garmin gave me the offer to get a replacement watch but I expect to get exactly the same basically useless watch.

Some background, I did a run (I expected it to take about 12 hours it took me 13h in the end but the watch just died after like 7 hours without any warning.
As I wanted to check how much battery would be left after this run I disabled everything except LTE to get good values Confounded But instead of measuring how much battery would be left I just ended up with a very frustrating run and nothing to show for it on Strava.

I did some research before and everyone told me a 945 should even last a slow Ironman without any issues which is why I wanted the watch.

After I found the LTE version of the watch I did some math:
GPS Mode without Music Battery Life: 35h
GPS Mode with Music Battery Life: 12h (lets say 40% of the time without music)
GPS Mode with Music and LTE2 LiveTrack Battery Life: 7h (which is like 60% of with music) 
As I didn't use any music and disabled literally everything I expected a little more than 60% of 35h (and Garmin is usually very conservative with their numbers)
Which amounts to about 21 hours and that sounded fine for me.

The Garmin support never gave me an answer if they were even working on fixing this.

Have you as a community ever gotten any better answer from the Garmin support regarding this issue?

(I know Garmin recently added a line "GPS Mode and LTE2 LiveTrack Battery Life" but that is still less than what I got and was definitely not there when I bought the watch)

 

  • 0 over 2 years ago

    ok, i may be wrong, but i think  the math needs to be done a little more carefully. if i recall, people were getting about 10 hrs for the scenario you list. here's my fast attempt at the math:

    GPS rate = 1/35 = 2.86%/hr

    GPS + Music = 1/12 = 1/35 + y 

    y= music burn rate = 5.48%/hr

    GPS + Music + LTE = 1/7 = 1/35 + 0.0548 + z

    z= LTE burn rate = 5.95%

    Therefore, for the case you cite: burn rate = 5.95% + 2.85%  per hour = 8.81% or roughly 11 hours of run time with GPS and LTE

    (no GLONASS or Galileo enabled else GPS burn rate is higher)

  • 0 over 2 years ago

    Yeah I have not exactly found out where my math is wrong but the math by derek87 sounds more reasonable. I didn't spend much time with this anyways because Garmin underestimates their battery lives on every other product I had. (Underestimate in a good way, I usually get a better battery life than the specification)

    The line: "GPS Mode and LTE2 LiveTrack Battery Life" is only in the English version, the German version does not have this line included which is why I did my own math.
    https://web.archive.org/web/20220710075640/https://support.garmin.com/de-DE/?faq=oU83zXuPHdAMHymFLDl8N9

    But my question stands, is something being done about this?
    There are several ways of improving the battery lives of IoT devices and I'm just wondering if we are ever going to see them in this watch.

  • 0 over 2 years ago in reply to Markus

    i hate to say it, but i think it is what it is. in my experience with the 945LTE, in GPS activity mode, it pretty much lived up to specs and as i calculated above, the different specifications are consistent with one another (with 10%), including LTE+GPS (not music).

    where the 945LTE falls short is in smartwatch mode. with the stock face and configured as they suggest, the watch will not hit the 14 day mark for pure smartwatch use which is disappointing to say the very least. it was about only 2/3 the battery endurance of my old 935 which lasted 16 days on my typical watch faces.

    i've sold my 945LTE to my friend, and i am happy to say that the 955 which replaced it does live up to smartwatch specs published. of course, it has a slew of bugs in its first couple months since release... (including some battery drain issues for ConnectIQ fields not disconnecting after an activity is done)

  • 0 over 2 years ago in reply to Markus

    my opinion is consistent with Derek’s - unlikely we’ll see notable improvements in power consumption from what you’re seeing.

    The LTE Livetrack “Power Save” is helpful to extend battery life (of course at a cost of rare updates).  DC Rainmaker also noted it will backfill the time gaps when intermittently checking in, but I don’t think it does that as the live track path is very rough with power save on.

    While the hardware may be a limitation (pure mA used per feature) I do wish there were some ways they could allow more tuning of things like the power save option - I.e. backfill gaps, user selectable check-in rate or some kind of manual trigger?

    Maybe this happens, but I’d also like to see an auto-power save / LTE disable at a battery threshold so in a long race you’d be sure to get your race data vs live track killing the battery (if it came to that level)

  • 0 over 2 years ago in reply to nord0296

    There are rules for radio frequencies and how many retries you can do so I guess the watch is already doing some checks on the network quality but the phrasing on the website leads me to believe that the watch keeps trying to send out data in areas with poor coverage which is a waste of energy.
    First, there should be beacon packages to check if the quality is good enough to send real data
    Second, after failed attempts, there should be increasing sleep times before the next attempt to send a package

    Both are mandatory to use the LoRa frequency so I guess LTE has to have similar rules. But I have no idea how the watches have LTE implemented and I trust that Garmin has real experts on this topic. 
    But my concern is if those experts are working on the 955 LTE or Edge LTE version or on improving the 945 LTE.