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Any issue with discharging battery?

LevMac

macrumors 6502
Original poster
Feb 23, 2008
412
2
QLD, Australia
Hey guys, its been twice since my watch has gone completely flat and I've had to charge it from 0%. Is it much of a problem if the battery completely dies off and then charging it back again? Or should you be charging it before it goes completely flat?

Thankyou
 

xraytech

macrumors 68030
Mar 24, 2010
2,518
212
Hey guys, its been twice since my watch has gone completely flat and I've had to charge it from 0%. Is it much of a problem if the battery completely dies off and then charging it back again? Or should you be charging it before it goes completely flat?

Thankyou

That is the worst thing you can do to the longevity of a Lithium Ion battery. Better to set it to charge when you go to sleep.
 
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LevMac

macrumors 6502
Original poster
Feb 23, 2008
412
2
QLD, Australia
I guess makes no difference if you let your battery discharge by 25% and charging it back up 100% four times counts as one charge cycle anyway
 

Mac2me

macrumors 6502a
Jun 10, 2015
965
445
OP, are you seeing it discharge at a rapid unusual pattern or is this just with a lot of use or maybe an app that sucks up battery? Reason I ask is that when I first got mine while it was on the charger the first or second night, I noticed it was discharging while on the charger. A hard reboot and that fixed it.
 

LevMac

macrumors 6502
Original poster
Feb 23, 2008
412
2
QLD, Australia
OP, are you seeing it discharge at a rapid unusual pattern or is this just with a lot of use or maybe an app that sucks up battery? Reason I ask is that when I first got mine while it was on the charger the first or second night, I noticed it was discharging while on the charger. A hard reboot and that fixed it.

Hey Mac2me, sorry should have made my post about clearer. It is not discharging on its own. My question was, is it harmful to have let the battery drain completely twice since I have had the watch? Im guessing it won't harm the battery, as it's no different to letting the battery drain to 75% from 100% and doing this 4 times, still completes ONE discharge anyway...
 

Mlrollin91

macrumors G5
Nov 20, 2008
13,685
9,277
Ventura County
Im guessing it won't harm the battery, as it's no different to letting the battery drain to 75% from 100% and doing this 4 times, still completes ONE discharge anyway...

The only time you should ever allow a lithium ion battery to completely drain is when calibrating it. Allowing it to completely die will indeed hurt the health of the battery in the long run. I never let any of my batteries ever drop below 20%.

Just because it still counts as one cycle doesn't mean anything. Lower the battery when you plug it in means a longer charge time. Longer charge time means higher temperatures. Higher temperatures shorten battery health. Therefore 4 charges from 75->100 is better than 1 charge from 0->100.
 

TrueBlou

macrumors 68040
Sep 16, 2014
3,951
2,709
Scotland
As above, spot on answer. Although I would say your not going to do any damage with the occasional complete discharge of the battery, just don't make a habit out of it.

Remember when a battery is quoted as say, 500 charge cycles, it doesn't mean that that's all it gets then it stops working. It just means that after that many full charge cycles it's no longer at its optimum.
However you'll usually find that by doing more frequent, smaller charges the battery will be in much better condition after the same length of time than it would be if you had done full discharges.
 
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LevMac

macrumors 6502
Original poster
Feb 23, 2008
412
2
QLD, Australia
As above, spot on answer. Although I would say your not going to do any damage with the occasional complete discharge of the battery, just don't make a habit out of it.

Thanks TrueBlou, I've had my Watch since launch day, and its only been fully discharged "twice" since and thats it.
Hopefully this isn't an issue, my OCD is kicking in now lol
 

Zxxv

macrumors 68040
Nov 13, 2011
3,558
1,103
UK
how can you manage to do short charges if you are out and about using it?
 

xraytech

macrumors 68030
Mar 24, 2010
2,518
212
how can you manage to do short charges if you are out and about using it?

If you're out and about using it... you're out and about using it. Don't think to much about it and keep it simple.

When you go to sleep, set you AW to charge. That's is really all you have to do.
 
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LevMac

macrumors 6502
Original poster
Feb 23, 2008
412
2
QLD, Australia
Thanks for the link.

So does one complete cycle also work in this way:
Charging watch to 100% then using it say until 70% then putting it back on charge to 100% (theres 30% charging)
Then after taking it off with 100% then using it until say 30% then putting it back on charge to 100% (theres 70% charging) which then completes one cycle right?
 

Mlrollin91

macrumors G5
Nov 20, 2008
13,685
9,277
Ventura County
Thanks for the link.

So does one complete cycle also work in this way:
Charging watch to 100% then using it say until 70% then putting it back on charge to 100% (theres 30% charging)
Then after taking it off with 100% then using it until say 30% then putting it back on charge to 100% (theres 70% charging) which then completes one cycle right?

Correct.
 

cowfish

macrumors member
Jul 23, 2009
46
16
Everything said so far is correct, except 0% charge on the watch is not actually 0%, at that point, I'm guessing the watch probably has around 15-20% battery left which is why the watch will work for around two days in power reserve mode, it doesn't run for two days on 0% and power reserve mode uses so little battery because it's basically doing nothing unless you want a quick glimpse of the time, that it probably only uses 5 of that 20% battery that is left. Apple isn't going to let you damage your battery by deep discharging that easily, that would be a lot of warranty replacements.

Also, don't take my numbers above as fact, I don't claim them to be, but you get the idea...
 
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LevMac

macrumors 6502
Original poster
Feb 23, 2008
412
2
QLD, Australia
Everything said so far is correct, except 0% charge on the watch is not actually 0%, at that point, I'm guessing the watch probably has around 15-20% battery left which is why the watch will work for around two days in power reserve mode, it doesn't run for two days on 0% and power reserve mode uses so little battery because it's basically doing nothing unless you want a quick glimpse of the time, that it probably only uses 5 of that 20% battery that is left. Apple isn't going to let you damage your battery by deep discharging that easily, that would be a lot of warranty replacements.

Also, don't take my numbers above as fact, I don't claim them to be, but you get the idea...

Thanks for your reply cowfish :)

So basically in other words, even though I drained my battery till it switched off twice over the past 2 months, there is no difference of completing a "full discharge" as it is the equivalent to charging methods as I mentioned above?

I just want to know that I haven't done anything "wrong" or "damaging" to my battery thats all. Will definitely not let it drain to 0% and past power reserve mode again.
 

cowfish

macrumors member
Jul 23, 2009
46
16
It should be fine. Like I said, I cannot say with 100% certainty as I don't work for apple or engineer this stuff, but I do know a little about li-ion and Lipo batteries and if past experiences with other apple products prove to be the same, there is a built in charge circuit that will prevent easily damaging the battery.

And yes, 30% + 70% battery levels before charging would equal one full charge cycle.

I wouldn't sweat it. There is a warranty on it if anything should ever happen, and if you haven't already, I highly recommend Apple care. I don't usually buy it for any of my other Apple products, but as cheap as it is you cannot go wrong with getting it for the watch.
 
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