Update: it seems that the best way to "Restart Device" is to connect the Charge 5 to the charging cable, then press the button on the USB end 3 times, holding the button down for 1 second each time.
I am consistently getting 6 to 8 days battery life with this procedure.
Original comments: I got my Charge 5, I immediately put it on the charger. The battery showed 54%, so I figured that with a "1 to 2 hour charge time", I could be up and running in a short time. Well, after an hour, it was only up to about 70%. At 2 hours, it was only at about 92% and it took a full 3 hours for it to finally come up to the 100% level. It hung at "99%" for at least 45 minutes and then it got to 100%. At this point, I was already beginning to doubt the charge estimate of "1 to 2" hours...
I waited until it discharged to around 50% (more than 4 days) before I charged it again, but this time it seemed to charge rapidly to 100% which I thought was odd. Again, I waited until it got down to around 40% (about 4 days), and then charged it again. This time, I charged it for about 5 hours while I was asleep. The battery lasted at least 6 days, even with workouts in there including walks with everything turned on including GPS, but I decided to charge it again when it got down to about 50%. It reached the "100%" level in a short time of about 2 and 1/2 hours, but it began to run down quickly. I decided to try the "Restart Device" setting to see if this would "clear the cache, restart GPS" or whatever might be running in the background, and the battery went back to a normal discharge rate.
On the next charge, I did the "Restart Device" function, then let the watch charge overnight. The watch easily lasted 8 days (yes, EIGHT) and still showed 35% charge. I did the Restart Device again and charged the battery overnight. It is still showing 93% after 8 hours and a long walk workout.
What would be causing this erroneous battery charge indication? Well, all Lithium-ion batteries must have an over-charge protection circuit so that they don't charge beyond their rated capacity. If this was allowed to happen the battery would over heat, cause a fire or explode, so the over-charge protection keeps the battery from ever getting to a "true" 100% capacity.
TAKEAWAY:
FIRST: I believe that FitBit needs to examine what they're using for an "over-charge" algorithm so that the charge indication is correct. Of course this means that they need to change their documentation to indicate the although the watch may be displaying "100%", it's not really there yet. My experience is that it takes a minimum of 3 hours and probably longer.
SECOND: FitBit needs to figure out what might be causing the quick battery drain on a fully charged battery. Having to use the "Restart Device" procedure is not out of the question, but should be indicated in their documentation.
So, I would be interested to hear what others might be finding if they use the "Restart..." procedure and give their watches a full nights charge. After all, do you really need sleep stats for every day of the week?
I hope this helps!
