Extend 6S GPS mode battery life beyond 25hrs?

I have a different model and I wouldn't start the race simply trusting the Garmin's own specs. I advise using chest strap as optical HR isn't as accurate as it. That way she can use a finger sized charger and do her activity without losing any data and with accurate data btw.

Yes- already discussed getting a separate HR monitor with her, and putting a charger in a drop bag.  So- I appreciate the advice, but was hoping for someone that can verify how much, if any, one can increase the 1-sec GPS life by turning off everything else.  ???

morey000 said:

If you turn off Optical HR, bluetooth, wifi, pulseOx, music... will the 6S go longer in GPS (1-sec) mode?  or does the 25hr spec already assume everything else is off?

The 25hr spec assumes OHR and BT are turned on. But it also assumes the "best" conditions - you don't have a course loaded / aren't using navigation features, you aren't getting any phone notifications, no screen backlight, not using the maps or breadcrumb trail datascreens, are using GPS-only (not glonass/galileo), etc.

If you only have OHR, BT, and GPS turned on, and are using minimal other features, then you'll get 25 hours. But as you use other features, that number will go down. In a 25-hour race, it's very likely that the backlight will be needed for at least some of it, so that alone is going to drop the battery time below 25 hours.

You can optimize the watch by using settings like "backlight only after sunset", phone notifications off, ultratrac mode instead of 1-second recording, and using a datascreen with fields that don't update very many screen pixels very frequently (time of day, average pace, distance, sunset/sunrise time, and battery are good examples of datafields that don't use much power).

But honestly, I wouldn't trust a 6S to make it the full 25 hours before dying, even in the best use case. I think if she's going to have any hope of making it last the full race, she'll need to make some big sacrifices, like turning off OHR for the whole run, not using backlight at all (even at night), not using any navigation functions... or resign herself to recharging the watch somehow mid-race. Or if cost is no object, get two watches - a 6S for "normal" daily usage, and a 6 to use for only ultra races.

It's also worth noting that when the battery dies, the watch does save the activity before powering off - so at least it's good to know that if the battery dies just before finishing, at least the data recorded up to that point will be saved.

I have a Marq Expedition with a power mode with GPS only, no BT, screen timeout, no OHR, but with HR strap allowed. That mode is supposed to extend battery life from 28 to 37 hours. But I haven't tested whether it holds true or not. Screen timeout works ok. 

Also using maps burns battery, and if navigation following a route is used even more battery is used. 

My preference for an event that approaches max battery capacity of the watch would be to bring a battery pack, and also use a HR strap for best data. 

C.sco said:

You can optimize the watch by using settings like "backlight only after sunset", phone notifications off, ultratrac mode instead of 1-second recording, and using a datascreen with fields that don't update very many screen pixels very frequently (time of day, average pace, distance, sunset/sunrise time, and battery are good examples of datafields that don't use much power).

Rather than messing round with datafields I don't actually want to use, I would just create a Power Mode with Display set to Timeout. This turns the display off completely, but reactivated by gesture whenever you actually want to look at it. Gives me a theoretical extra 8 hours on my F6 - not sure what it would give on a 6S.

Also, for an event that long that was so close to the rated specs, I would plan on using a lipstick battery to recharge - even a couple of 5 minute top-ups at aid stations/bag drop will make a significant difference to overall battery run time, and allow for some moderate backlight usage overnight. I'd be gutted if I did an event this long and my battery died on the final loop - it seems a small precaution to take to avoid this.

Well the screen draws negligible power when it's not constantly updating tons of pixels, which is why these watches can go weeks in smartwatch mode with the screen always on. So using datafields that don't update many pixels frequently (on an always-on screen) will gain about the same amount of battery life you gain by using the display timeout. But like you said, the screen timeout would allow you to have any datafields you want, so that's also a plus. So it just depends on one's needs I guess.

Definitely agree about the battery charger - I have one that is shaped like a thick credit card and only weighs 3 ounces (85 grams), and has enough juice to charge the watch 4-5 times.

There several things that can be done to extend battery life - it is easy to do that in Power manager and see the exact estimate:

- Turn optical HR off

- Switch to GPS only (from GPS+Glonass)

- Turn Bluetooth off

- Turn screen timeout on

- Turn autolap off

- Turn map screen off 

By making these changes on my 6X pro the estimated battery life goes up from 60 hours to 87 hours.

C.sco said:

The 25hr spec assumes OHR and BT are turned on. But it also assumes the "best" conditions - you don't have a course loaded / aren't using navigation features, you aren't getting any phone notifications, no screen backlight, not using the maps or breadcrumb trail datascreens, are using GPS-only (not glonass/galileo), etc.

Well- she'll definitely have the course laid in for navigation, although I thought that only really used much more power when you are on the map screen?  Although, now that I'm thinking... every friggen switchback tells me to turn... with a light and a vibrate... twice- so that will certainly suck down the power.  She'd have a separate HR monitor.  

silentvoyager said:

By making these changes on my 6X pro the estimated battery life goes up from 60 hours to 87 hours.

That's some pretty big improvement in time.  The same ratio for a 6S- would take it form 25 to 36hrs.   But, then she'll want navigation.  

thanks for the info.  

silentvoyager said:

exact estimate:

morey000 said:

That's some pretty big improvement in

..estimation. In reality it might not be so much. I am not aware that anyone has pushed the 6X that far.

To get back to the OP - basing a successful outcome on the estimated life (exact or otherwise - BTW how can an estimation be exact?) might not be a good idea.

The 6S has a small battery. As already noted I would recommend top-up charging at aid stations throughout the run. Since it's a 100 miler I would suspect some of the stops will be longer than one would normally take. At the aid stations I'd suggest she stop the watch, select Resume Later, put it on charge for the time she's stopped, then resume.