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lhs11

macrumors newbie
Original poster
Aug 24, 2017
3
0
I've been using my 2016 13inch MBP for about 9months now,
and I had been maintaining pretty good battery health over the 9month, keeping the battery health at 100%
But for some reason over the past 3days the battery health dropped to 98% and it's getting me all paranoid!
What would I have possibly done that could drop 2% of it over 3 days?
My battery cycle is at 39

Any tips or pointers on how to keep best battery condition?
Just having it plugged 24/7 the best way for this?
 

Bending Pixels

macrumors 65816
Jul 22, 2010
1,307
365
Like muscles, you need to exercise the battery. That means unplug it and use it on battery power for a while. Leaving it plugged in and never running on battery power can actually degrade the battery life.
 

Patcell

macrumors 6502a
Aug 8, 2016
634
302
Bergen County, NJ
This is the age-old question...

Very true that you should not leave the machine plugged into power 100% of the time. People get caught up in keeping the cycle-count as low as possible, but that can be a detriment also if the battery is never used.

I used to watch the battery health like a hawk and constantly obsess over the number, but recently I have decided to let it go... and I’m happier for it. My advice is to use the machine as it was intended to be used; if you are at your desk, plug it in, if you’re on the go, use the battery.
 

tmt

macrumors regular
Mar 8, 2009
102
42
I´m with KGB7 on this one. Every time there is an update to macOS I let it discharge and then let it be without plugging in for at least a couple of hours. Then charge it to 100 %. Keeps the battery nice and fresh.
 

ZapNZs

macrumors 68020
Jan 23, 2017
2,310
1,158
Shifts in health statistics are normal. A 2% shift is statistically insignificant.

Light discharges place less wear on the battery than deep discharges. If you use the battery frequently and only run it down say from full capacity to three-quarter capacity and then recharge, this places little wear on the battery and in some cases may prolong life more than simply leaving it in a constant fully-charged state. Deep discharges place a huge amount of wear on lithium cells.
Long periods at fully charged capacity causes wear.
Long periods at very low capacity causes rapid wear.
Heat expedites wear...rapidly (ironic, right?)

The battery will wear no matter what - whether you use it or not. Given the cost of replacement is not terribly high, the lifespans are reasonably long, and AppleCare covers replacement, the best thing one can do is IMO enjoy it and not allow worry over battery health to cause modifications to usage patterns that cause inconvenience.
 
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Falhófnir

macrumors 603
Aug 19, 2017
6,146
7,000
Keeping a li-ion battery at 100% charge isn't good for it's lifespan, between 20 and 80 percent is optimal really. Closer to 50% you can keep it the better. Really you should just use it and not worry though, if you need to you can get the battery replaced. It's just not worth the hassle of trying to 'maximise' your battery's lifespan, in the end it probably won't make a noticeable difference either way, but you'll have driven yourself to distraction. Cycles = wear is more or less a myth. Yes it will degrade somewhat each time you charge up/ deplete, but if you do it in smaller chunks, that's putting less strain on it than one big fully charge/ fully drain, and probably even constantly on a/c at 100%.
 

KGB7

Suspended
Jun 15, 2017
925
753
Rockville, MD
Here is a big tip i can give you about batteries to prong their life that i have learned.

When you discharge the battery down to 50% or to 5%, let the battery sit for few hours while the laptop is off before recharging it. Once fully charged, let the battery settle down for few hours before you use it again.
The science behind it as it was explained to me; is during a charge or discharge, there is a chemical reaction with in the battery. So you want to wait 1-2 hours before using it or charging it, to let the chemical reaction settle down.

Having that said. If you cant wait and you need to use your laptop, go ahead and use it, you wont damage the battery.
 
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Patcell

macrumors 6502a
Aug 8, 2016
634
302
Bergen County, NJ
Shifts in health statistics are normal. A 2% shift is statistically insignificant.

Light discharges place less wear on the battery than deep discharges. If you use the battery frequently and only run it down say from full capacity to three-quarter capacity and then recharge, this places little wear on the battery and in some cases may prolong life more than simply leaving it in a constant fully-charged state. Deep discharges place a huge amount of wear on lithium cells.
Long periods at fully charged capacity causes wear.
Long periods at very low capacity causes rapid wear.
Heat expedites wear...rapidly (ironic, right?)

The battery will wear no matter what - whether you use it or not. Given the cost of replacement is not terribly high, the lifespans are reasonably long, and AppleCare covers replacement, the best thing one can do is IMO enjoy it and not allow worry over battery health to cause modifications to usage patterns that cause inconvenience.
This 100%. Excellent write-up of battery use and wear, IMO.
 
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KGB7

Suspended
Jun 15, 2017
925
753
Rockville, MD
By the way, the health number will fluctuate normally. Very likely that your reading of 98% health will be back to 100 after a couple days use.

That is correct, numbers will fluctuate due to chemical reaction. Controlling those chemical reactions as a consumer with out expensive equipment is nearly impossible. .

We also have to take into consideration the accuracy of the software and sensors it uses to measure the health of the battery.
Laptops, iphone, ipads, aren't built around a battery with sensitive and expensive sensors just for the sake of monitoring a batteries health.

So when ever you using an app to check your batteries life, take that information as a point of reference and not a true scientific measurement.


At the end of the day, my best advice i can give is; dont let OCD or OCD like thoughts control you. Its just a battery, that can be replaced for a very low price.

Your heart, your mind, and body well being are FAR more important than few ounces of chemicals in a laptop.
 

Patcell

macrumors 6502a
Aug 8, 2016
634
302
Bergen County, NJ
That is correct, numbers will fluctuate due to chemical reaction. Controlling those chemical reactions as a consumer with out expensive equipment is nearly impossible. .

We also have to take into consideration the accuracy of the software and sensors it uses to measure the health of the battery.
Laptops, iphone, ipads, aren't built around a battery with sensitive and expensive sensors just for the sake of monitoring a batteries health.

So when ever you using an app to check your batteries life, take that information as a point of reference and not a true scientific measurement.


At the end of the day, my best advice i can give is; dont let OCD or OCD like thoughts control you. Its just a battery, that can be replaced for a very low price.

Your heart, your mind, and body well being are FAR more important than few ounces of chemicals in a laptop.
Very well-said! Thank you.
 
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odoy

macrumors regular
Aug 4, 2015
124
45
Germany
Any tips or pointers on how to keep best battery condition?
Just having it plugged 24/7 the best way for this?

My tip, don't think about your battery ;)
 

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lhs11

macrumors newbie
Original poster
Aug 24, 2017
3
0
Never mind guys!
you guys were right, it climbed back to 100%!
 

maerz001

macrumors 68030
Nov 2, 2010
2,525
2,430
paranoid for 2% in 9 months:)
how many decades have u planned to use this computer?
 

ZapNZs

macrumors 68020
Jan 23, 2017
2,310
1,158
If you want to be super paranoid about battery wellbeing, here are some expanded points I posted in another thread that we could modify/add to.

----------------
The battery will wear no matter what - whether you use it or not. Given the cost of replacement is not terribly high, the lifespans are reasonably long, and AppleCare covers replacement, IMO the best thing one can do is enjoy it and not allow worry over battery health to cause modifications to usage patterns that cause tremendous inconvenience. At the same time, a basic understanding of lithium cells provides the User with the basic knowledge needed to maximize the lifespan (and safety) of any portable devices powered by rechargeable lithium batteries.

I'm far from an expert here, but here are some things to keep in mind that applies to LITHIUM cells...
  • Many of the basic handling/usage/charging/care/safety guidelines that apply to NiMH and NiCad rechargeables are NOT the same with lithium rechargeables. - For example, where as NiMH and NiCad can be used safely with continuous trickle charging (although this is not optimal for longevity), lithium charging must terminate at a specific voltage (often 4.2v) or else they can enter a dangerous state of overcharge, sometimes ending in a vent-with-flame (i.e., it ends with what most people would essentially call an explosion, and when a lithium cell vents it can set other things on fire.) Cheap lithium chargers/batteries carry an inherently greater risk because, should the charger fail to terminate charging at the correct peak voltage, and, should the battery's protection circuits fail to break the connection to a malfunctioning charger (or should the battery not have its own protection circuit at all), the battery could continue to charge right up until it vents-with-flame. (This has happened quite often in the world of eCigarettes, where someone uses a terrible quality 'super-fast' charger, a terrible quality battery, and it ends badly.) Further, crappy chargers may attempt to charge a severely over-discharged battery, and crappy batteries may have crappy protection circuits that allow the battery to be recharged even after an extended period of over-discharge (this is hazardous and can end in a vent), and crappy batteries/chargers may fail to detect early signs of thermal runaway from other causes (also hazardous and can end in a vent.) The stakes are arguably higher here, and the efforts made towards safe operation are sometimes lacking when considering the risks.
  • If convenient, recharge your battery once it hits around 75% - Light discharges place less wear on the battery than deep discharges, and lithium cells do not have a memory effect. If you use the battery frequently and only run it down say from full capacity to three-quarter capacity and then recharge, this places little wear on the battery and in some cases may prolong life more than simply leaving it in a constant fully-charged state.
  • Frequently running your battery down to the point of being near empty will shorten the service life significantly - Deep discharges place a huge amount of wear on lithium cells. For example, running the battery down to only 5% remaining capacity and recharging it just one time could place more wear on the battery than running it down to 75% capacity and recharging it 10, 20, or 30+ times. Apple cycle counts DO NOT REFLECT THE SPECIFIC DEPTH OF DISCHARGE! Consequently, cycle counts say only a limited amount regarding battery wear.
  • If your computer is usually plugged in, occasionally running it down to 75% capacity and recharging may extend its service life - Long periods at fully charged capacity causes wear because at 100% capacity, the battery is at its maximum voltage, which is higher than the nominal voltage, and this places stress on the battery. A battery that is never used and always fully charged will still wear even without usage.
  • Leaving your battery at extremely low or empty capacity is one of the worst things you can do, and doing this often will rapidly reduce the battery's service life - Long periods at very low capacity causes rapid wear - in some cases, this can destroy the battery.
  • Frequently storing your laptop in a hot car or sitting in bright sunlight will dramatically shorten the lifespan - Heat expedites wear and it is arguably the biggest single enemy of lithium cells (ironic, right?)
  • There is no such thing as a "calibration discharge" or "battery calibration" on modern Apple laptops with OEM internal batteries - running the battery all the way down on a set schedule wears the battery and may not improve reporting accuracy anymore than a SMC reset. (Note that some third party companies that sell 3rd party Apple-compatible batteries advise performing calibration discharges.)
  • Applications that report on battery health statistics are not necessarily accurate. Further, the metrics that the battery reports (such as a health %) can fluctuate somewhat on a day-to-day basis - The value of these battery metrics are IMO limited, and the biggest single indicator of battery health should be the real-world runtime.
 
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Samuelsan2001

macrumors 604
Oct 24, 2013
7,729
2,153
The battery health myths are myriad and nonsense. By far the biggest issue for Modern batteries is age, your battery will need replacing sometime between 3and 5 years old nothing you can do will change this, little you can do will push it to the longer end of the scale. It will happen when it happens and seems far more down to the individual battery than anything the user does.

You bought a laptop to have a portable computer that runs on battery when needed use it as you want, forget about the battery and treat it as what it is, a tool to use as it was intended to be used.
 
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ZapNZs

macrumors 68020
Jan 23, 2017
2,310
1,158
The battery health myths are myriad and nonsense. By far the biggest issue for Modern batteries is age, your battery will need replacing sometime between 3and 5 years old nothing you can do will change this, little you can do will push it to the longer end of the scale. It will happen when it happens and seems far more down to the individual battery than anything the user does.

You bought a laptop to have a portable computer that runs on battery when needed use it as you want, forget about the battery and treat it as what it is, a tool to use as it was intended to be used.

Apple batteries can last far longer than 3-5 years!!!! - the question is whether or not the User wishes to go to the trouble to preserve them, given a battery service is not priced like a Rolex service. I agree there can be huge variation among individual units outside of the User's control.

Many of the batteries in Apple laptops that I check in that have extremely early replacements are frequently run down in very deep discharges. Depth-of-discharge (DOD) unquestionably has significant impact on the lifespan of the battery, and for that matter all (rechargeable) lithium cells in general.
 

prisstratton

macrumors 6502a
Dec 20, 2011
543
127
Winnipeg, Manitoba, Canada
When I first got my MBP I used to obsess about the battery until I read a few threads on this forum. After that I quit worrying about it and just used it as needed and plugged in when not (pretty much what @odoy and everyone else is saying).

Just about coming up on 6.5 years and still chugging along.

Screen Shot 2017-09-21 at 10.10.38 PM.png
 

polbit

macrumors 6502a
Sep 18, 2002
528
650
South Carolina
We still have an early 2011 MBP 15" in the house, and the battery has finally given up the ghost. 1,100 cycles - still keeps charge at around 70%, but it spikes down causing a shutdown when it gets warm.

Honestly, just use it. It will last a good number of years, and the replacement is not that expensive.
 

pejx72

macrumors newbie
Jun 20, 2017
17
12
As I understand it, a lithium battery is best stored at around 50% of full charge. Having recently moved from Lenovo Thinkpads to Mac, I was disappointed to find that Apple don't have a feature in Mac OS that allows you to manually stop the MacBook from charging its battery at 50%, or indeed any % except 100%.

My solution. I discovered by accident that the 12W Apple iPad charger (model A1401) provides exactly the right amount of power to run a MacBook in normal usage conditions, but without charging the battery. Problem solved. Unless someone can explain to me that this is somehow a bad idea?
 
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