What's your typical battery life?

I have not tried 100% to 0% yet, since I usually charge the watch when the battery level is about 20%. And I am not really keeping track, but I think I get about 4 days, before recharging. In these 4 days I use the GPS about 3-4 hours.

When I look at your experience you have used GPS for 3 hours (I assume you have GPS turned off during yoga, and yoga does not use any extra battery) and used the watch for 3.16 days and your battery is at 33%. So I think it is quite similar to mine.

According to Garmin’s specs you get up to 7 days in Smartwach mode. That means only using it as a watch and not use the GPS and/or music, but most of us won’t use the watch like that. When I use the watch with GPS, it uses about 8% per hour, which would mean 12.5 hours in total on GPS. That is 1.5 hours less than Garmin’s specs, but I am still happy with it.

Since the watch charges very fast, I don’t have any issues to charge it twice a week.

Same here , about 4 days . Run every day between 30 mins and 1.30 . I have all notifications turned off and backlight off and expect less if I use music.
Happy with the battery life considering the smaller size and therefore battery size, charge time is great so for a modern device I think it performs fine wish my phone lasted 4 days ????

I forgot to mention that I have notifications turned on (about 10-20 per day on average) and the backlight only turns on on button press.

Four days seem to be the norm for me as well. I have all notifications/features enabled. I do about four 30-45 minute runs during the week with music, GPS, and ANT+ enabled. I also do two to three biking, strength, or other non-GPS activities where I'm just wearing my chest strap and listening to music. On the days that I charge the watch, it's usually sitting at 14% battery remaining or so. While the watch's battery doesn't last as long as it does on my Fenix 3 HR, I definitely wouldn't say that battery life is horrible on the 645M. Considering the watch is at least twice, if not more, powerful than my Fenix I am quite happy with the performance and battery life.

Recently started tracking my usage as I'm not sure on battery life...

17/07 07:30 @ 96% to 20/07 22:55 @ 23%
6 non gps workouts totalling 1hr 19min


20/07 22:55 @ 100% to 23/07 18:35 @ 30%.
3 gps activities totalling 3hrs 15min
1 non gps workout 22min

gps used approx 15% during the first activity of 1hr 22min



I have no notifications or backlight on with 1 daily alarm.

Not sure if this is acceptable as it seems worse than the usual.


Thoughts anyone?

I get 4-5 days per charge. Typically I charge when the battery level drops below 10% and have gone as low as 2% with no issues. My use pattern has been at least 4, 1-hour, GPS activities over a 5 day period and longer GPS activities on the weekend. Two weekends ago I charged on Friday, used it for 5 hours of GPS on Saturday and then 1 hour on Monday, Tuesday and Wednesday, charging the watch on Wednesday evening when it got to 15% or so. I use a cadence sensor when cycling and a foot pod when running. I have not had any odd rapid-power-loss events.

FYI: the charge indicator seems to "stick" in the high 90's for some time, drop at a 20% per day rate "ish" through the midrange and then drop very slowly from 15% and lower. I don't know if this is typical, but it is what I have observed.

I also get about 3-5 days; I don't have the M. I'll lose 9-10% battery for an hour run, and anywhere from 8-10% additional over a day. I charge in the morning if I notice my remaining battery is 2X% and I usually try to stop charging it in the 8X% for longer term battery life. It's harder to catch it in the eighties. With the new charging cable of the 645 it charges much faster than my 235 did.

I get about 4 days max with about 2-3hrs of running (GPS+GLONASS) and some stats browsing. What are some good tips/settings to extend the battery life?

I’ve had a 645 non-music for a week.. picked up Saturday 20th July.

Fully Charged on Monday evening.
Most settings on default (backlight, WiFi, BT, HR monitoring - including nighttime) and lots of notifications (which i will probably turn reduce)
Also a lot of the normal “chimping” with a new watch.
Not much activity tracking - too hot during week, maybe 45m total.

On Saturday morning i woke up with 23% remaining.
Instead of charging, i though i’d push on and see how the battery lasted.
45m running in the morning (after which i was down to about 14%
61m walking in the afternoon.... started at 9%, and reached my front door with 1% remaining (4pm).

i decided to save my walk, and then start a new walk to see what would be happen when i hit zero.
after about 400m i hit 0%, then after a further 250m watch died.
got back home and re-charged (only took about 75m to hit 100%)
went to garmin app to see if the walk was saved, and all but the last 50m was there.

Next I’m going to experiment with ultratrac - particularly for walking (any way to make it the default for walking?), and other batter optimising.
I think 4-5 days with my type of usage is going to be about right.
It’s a huge improvement on my wretched Apple Watch 2 (in many ways)

Ok, so it looks like 4-5 days with typical usage for most of us. I guess that's ok. I was hoping i would get a week out of it. But, it really charges quickly so I am pleased with that.