When should I charge my battery?

Learylvr.

macrumors regular
Original poster
Nov 18, 2011
202
3
I’ve had IPhones since the 4 so I should know this. I now have the IPhone Xs Max. What percentage should I let my phone get down to before I charge it?? I want to keep my battery healthy and get the best performance from it. Does it hurt to plug it in when in the car, even if the battery isn’t low? I usually try to drain it once a month before plugging it in to keep it calibrated. Is this necessary? Thanks for the tips and advice.
Cheers
 

Learylvr.

macrumors regular
Original poster
Nov 18, 2011
202
3
Well thanks that’s exactly what you needed to know.. One last question.. if I’m sitting next to a charger should I plug in even if I have
Plenty of battery? Like when in the car or sitting at a desk for example. I’m not sure if just constantly plugging in for a charge (even if I don’t need one) is bad for my battery or makes it weaker over time. Thx so much for the tips..
Cheers
 

C DM

macrumors Sandy Bridge
Oct 17, 2011
48,583
17,219
Realistically whenever you want. The batteries and charging circuitry are set up in such a way these days that you won't really be in a state where you'd do anything that's really noticeably damaging to the battery. Mainly it's the heat that you'd want to avoid--either leaving or using the phone where it's hot or if it's heating up for some reason for an extended period of time while doing something.
 

JPack

macrumors 603
Mar 27, 2017
5,696
8,685
The only thing I would avoid is charging in your car.

Most of the USB cigarette adapters on the market are poor at regulating voltage fluctuations. The socket can output up to 14V and unless the adapter is well built, it can damage your phone.
 
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C DM

macrumors Sandy Bridge
Oct 17, 2011
48,583
17,219
The only thing I would avoid is charging in your car.

Most of the USB cigarette adapters on the market are poor at regulating voltage fluctuations. The socket can output up to 14V and unless the adapter is well built, it can damage your phone.
Doesn't the phone ultimately regulate the amount of charge it can actually take (as in higher powered chargers won't necessarily charge the phone faster if the phone doesn't support that level of charging)?
 
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JPack

macrumors 603
Mar 27, 2017
5,696
8,685
Doesn't the phone ultimately regulate the amount of charge it can actually take (as in higher powered chargers won't necessarily charge the phone faster if the phone doesn't support that level of charging)?
The phone can regulate the input current, but it expects steady voltage (5V) coming in. In most cases, the cigarette plug in a car wasn't designed to power sensitive electronics.

A genuine Lightning cable can stop voltage fluctuations but I'd suggest stopping the problem at the source.

https://www.discdepotdundee.co.uk/apple-tristar-u2-repair-and-cheap-lightning-cable-damage/
 
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AxlTJ

macrumors regular
Aug 3, 2018
101
19
It's been a known fact that lithium-based batteries benefit from the 80/20 cycle charge. However, there are also other factors to consider in keeping the battery healthy such as extreme temperatures, stress (like running multiple apps at once), charging at fluctuating voltages and etc. That said, to maintain battery health, one must take all these factors into account than just focusing on the charge cycle.
 
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Learylvr.

macrumors regular
Original poster
Nov 18, 2011
202
3
Thank you everyone, that is plenty of info for me and exactly what I wanted to know.. I know quite a lot about IPhone/Android.. but the battery care has always fallen short. Thanks for the help and tips.
Cheers
 

1050792

macrumors Demi-God
Oct 2, 2016
2,515
3,989
Never read so much nonsense like on this post. iPhone batteries like all Lithium-ion batteries are designed to charge in cycles and meant to charge whenever you need or want. The 20% and 80% charging thing is a total nonsense since after 80% until 100% iOS limits the battery charging speed so it won't cause any damage to the battery.
More information at
https://www.apple.com/batteries/why-lithium-ion/
 
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C DM

macrumors Sandy Bridge
Oct 17, 2011
48,583
17,219
Never read so much nonsense like on this post. iPhone batteries like all Lithium-ion batteries are designed to charge in cycles and meant to charge whenever you need or want. The 20% and 80% charging thing is a total nonsense since after 80% until 100% iOS limits the battery charging speed so it won't cause any damage to the battery.
More information at
https://www.apple.com/batteries/why-lithium-ion/
It's not really nonsense, it doesn't seem that anyone is saying it's harmful to go beyond 80% or anything like that, just that it's best/better when the battery is mostly in the 40%-80% range. That said, how much of a real world benefit that would bring, especially when compared to the hassle of keeping an eye on it all and all that, ultimately makes it something that isn't really all that worthwhile to really bother with.
 
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eyoungren

macrumors Core
Aug 31, 2011
22,116
14,845
ten-zero-eleven-zero-zero by zero-two
I tend not to concern myself with the battery and just use my phone.

My phone goes on charger at night with the screen on all night (nightstand clock with a black background). I get up at 5am and the phone is off charger until 10 or 11pm.

When I go to bed I have anywhere from 70-75% of battery left. But whatever percentage it is I put it on charger anyway at night.

I've done this for three years now. I did it with my 6+ for seven months, my iPhone 5 for two and a half years and a 3GS for nine months before that. I've never had any issues.

One of the popular battery apps tells me that my battery has 14% wear. I've been told that heat has an effect on battery, so I guess this is pretty good considering the phone has spent two summers of Phoenix, AZ heat going around in a car with no A/C and windows that are stuck closed.

All of this said, I don't use my phone like most people seem to do. Calls, texts, email and light web browsing.

I'm on iOS 9.0.2 if that matters to anyone. No CPU throttling due to battery.

EDIT: Oh yeah. My phone is never turned off (it's on 24/7). I cannot recall the last time I had to plug it in because the battery was too low.

My wife's 6+ is similar, but she uses her phone a bit more than I do.
 
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Irock619

macrumors 68000
Sep 16, 2011
1,772
275
San Francisco, CA
I’ve had IPhones since the 4 so I should know this. I now have the IPhone Xs Max. What percentage should I let my phone get down to before I charge it?? I want to keep my battery healthy and get the best performance from it. Does it hurt to plug it in when in the car, even if the battery isn’t low? I usually try to drain it once a month before plugging it in to keep it calibrated. Is this necessary? Thanks for the tips and advice.
Cheers
Do you upgrade every year?
 

C DM

macrumors Sandy Bridge
Oct 17, 2011
48,583
17,219
If you intend to use your phone for a long time, its best to keep it plugged in as often as you can. This will remove the number of charge cycles your phone goes through thus giving it greater battery life.
How would that remove charge cycles?
 
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