It seems to be a Garmin 'thing' to report battery SOC in terms of days rather than % which can be really frustrating as you don't know what they're basing that prediction on: Is it just a generic algorithm, or is it based on my own usage patterns? Either of those are probably going to be wildly inaccurate. And what about solar? Does it make any assumptions there? Reporting SOC by % can cause some confusion as discharge tends not to be linear (though they could still account for that), but it's still way more useful than predicting how many days it will last.

Check the thread. I just post there where to find % and solar effectivity.

G1 solar efficiency

I can say so far that the algorithm to calculate the remaining days is really very basic. In my case it always shows battery % divided by 5. So basically no matter how much I use the watch or whether I charge it with the Sun or use GPS activities it always assumes that 5% is 1 day. Starting with 20 days when it’s full and 2 days if it’s 10%. In real life I empty the battery in 6-7 days so the “days remaining” indicator is simply useless and false. I’d much preferred to have battery percentage on the original watch face or some more intelligent algorithm. 

Hi Corkef, I say your post and thank you for the info, I realise that I can get the info by scrolling either up or down but I'd like the % info to be the default on my main display.
As both NeilJonesOnline and 8runocsd  said, as inaccurate as the % may be, it seems more informative to me than days remaining (that just varies wildly) and is also more pleasing to my eyes I guess haha.

May I ask what your use of the watch is to empty it in 6-7 days? I feel like I could have it last 10 to 14 days but as soon as I go kitesurfing or diving it goes down quite a bit for sure. I try not to charge it all the way to 100% (90 usually) but I'm not sure it helps in any way to preserve the battery in the long run.

• Usually it’s one or two walk activities (all together about an hour) per day. Then 3-4 open water activities (20 minutes each)  plus 1-2 pool swimming (1 hour each) per week. If it’s a busy day it can easily eat 20% battery. Day without any activity or just one 30 minutes walk can be 7-8%. Solar charging works mostly when outside and can add additional 2-3% per day - not much. 

Hellooo,

Well after a week I'm reluctantly getting used to it but I feel like the battery life is not as good as advertised ; and maybe got worse with the update, is that possible?...

Last weekend I used up more than 11/12% of battery on an hour long dive, that does NOT add up to the 25 hours advertised, even on the non solar model. I had no fancy settings that would drain the battery, does the HR monitoring drain up a lot of power?

I just charged it up to a 100% and am closely watching the battery usage (normal usage, no phone connection, no GPS, went from 100 to 99% real quick but I guess the last % doesn't mean much) and feel like there is not way it holds for even 21 days; or am i supposed to use the battery saving mode for this? I also turned off Move IQ, I feel like I don't have much use for it and it might be draining the battery.

Sorry about the rant I feel like this is the best place to have it haha

EDIT : So I'm down 8% in about 24hours, no GPS and just some fiddling in the settings of the different apps, I'd love some feedback from others users to see if my G1 (solar but I don't get that much sun daily) is depleting faster than normal or I'm just expecting too much out of it.
I won't charge it for the next weeks (if it holds that much) and report the battery usage here to see what a full cycle gives me.

Kind of similar experience. I can't complain though, compared to my previous Forerunner 45 the battery is incredible. I must have 2 hours of diving, 8 hours of GPS activities since last charge 9 days ago, and the battery is now at 24%.

But that said, I also feel like the battery is now as good as advertised. Maybe a firmware update will add some improvements...

I'm not convinced that the remaining battery status even works properly with solar. I alternate between my Descent G1 and my MARQ and when I'm wearing my MARQ, my Descent has been sat on the windowsill in full sunshine for several days. When we just have a moderate amount of sunshine, the level on the Descent stays the same (e.g. 5 days) as I'd expect. However, even when it's sat in intense sunshine for several days (the solar intensity is maxed out for 6+ hours each day), this never goes up at all which doesn't seem right.

EDIT: thinking about it, it may be that the watch will run directly off solar if the sun is shining, but the solar unit doesn't actually charge the battery, which would account for the above. That isn't generally how solar+battery devices work though in my experience.

One thing to keep in mind is that if the watch overheats, it doesn't charge. It's not supposed to stay still under the sun, it will get horribly hot. If you want to test the charging capabilities either the watch should be on your wrist, either moving, or else maybe have a fan blowing air at the watch to make sure it doesn't overheat. I watched many reviews about that on youtube previously