iPhone XS Max Why Cycle Battery on Low Charge?; Worth It!?!

Discussion in 'iPhone' started by ShMac, Oct 9, 2018.

  1. ShMac macrumors member

    Joined:
    Sep 3, 2007
    #1
    My new phone, and especially my new iPad, seem to have decent battery life. Charging has not been much of a problem yet.

    I see a lot of people using low wattage chargers in their cars, such as the 7.5 watt induction models. This might make sense if you are going to upgrade every year, or every other year.

    But, I buy my devices and use them longer than many people. I have a 4 year old Motorola Android phone and the battery works decent even now.

    Is it really worth it to have a car charger cycling the battery to add a tiny bit of charge here and there if you wish to keep the phone longer?
     
  2. Newtons Apple macrumors Core

    Newtons Apple

    Joined:
    Mar 12, 2014
    Location:
    Jacksonville, Florida
    #2
    Unless you live on your phone and the battery will not last a day, there is no reason to charge it during the day.

    I put mine on the wireless pad each night before I go to bed and it is ready in the morning.

    The X I just retired still had 100% battery health after a year of this so I hope my MAX does the same.

    Best to not waste your time worrying about your battery.
     
  3. BigMcGuire, Oct 9, 2018
    Last edited: Oct 9, 2018

    BigMcGuire Contributor

    BigMcGuire

    Joined:
    Jan 10, 2012
    Location:
    California
    #3
    Just making sure I understand correctly --- you do realize that charging your phone 90%-100% is only 10% of a cycle right? So it really doesn't matter if you charge 20 times a day or one big charge at the end of the day. I do like @Newtons Apple way of charging and do it myself, but just making sure you know that you can plop your phone on a charger anytime, and it doesn't waste your battery or burn through charge cycles at a greater rate than one charge a night.

    Your phone will always use battery even at 100% - the phone cycles 95-100% plugged in or sitting on a wireless charger. Unlike a laptop (or Macbook) that will disconnect the battery and run purely off of wall power and consume no cycles for long periods of time - your phone's only source of power is the battery.

    https://www.apple.com/batteries/why-lithium-ion/ (see It Makes Charging Easier part).

    I have a wireless charger at my desk, at home on my desk, and I plop my phone down on them whenever I can. On my drive to work (50 mins) my phone is plugged into my car via CarPlay. I still average near 170-200 cycles a year.


    Constantly draining a phone down to 0% to charge it is excessive wear. Shallow charging (frequent) is better. https://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries See the depth of discharge part.

    But yeah... @Newtons Apple is 100% correct. My wife drains her phone constantly, burns through many more cycles because she uses her phone more. Her health % is just a few off from mine even though I "baby" my battery.
     
  4. ShMac, Oct 9, 2018
    Last edited: Oct 9, 2018

    ShMac thread starter macrumors member

    Joined:
    Sep 3, 2007
    #4
    Thanks for the great reply. I have found lithium batteries to vary greatly in quality through a lot of both research and experience.

    Even with Apple computers I have rarely found the batteries to last nearly as well as advertised while keeping them topped up, plugged into the wall wart most of the time. So, I am not just ready to assume this is the correct advice. Are the batteries in the iPads or iPhones different than in the MacBook Pros!?!

    In fact, I've found it comes down to the specific lithium technology involved. There are many and they are also, again, of varying quality and other characteristics.


     
  5. now i see it macrumors 68040

    Joined:
    Jan 2, 2002
    #5
    If you lived on Mars and had no way to replace the battery for the life of the device, the best way to keep the battery last as long as possible would be to keep the charge level always between 65% and 75% and never charging to 100% or discharging below 40%. But this type of extreme usage essentially limits your battery capacity to a small percentage of its usable capacity.

    If you used the battery like this, it would easily outlast the life of your phone, so one day you'd have a dead phone on Mars instead of a dead battery.

    These iPhones can't last forever.
     
  6. BigMcGuire, Oct 9, 2018
    Last edited: Oct 9, 2018

    BigMcGuire Contributor

    BigMcGuire

    Joined:
    Jan 10, 2012
    Location:
    California
    #6
    Agreed about batteries varying greatly in quality. I've found with iPhone batteries that it really doesn't matter how you treat them it usually handles pretty well. But draining to 0% frequently seems to be detrimental, most detrimental being high heat -leaving in the sun, using the phone till it shuts off from thermal overheat. As long as you don't do these, usually you'll be ok.

    I think Apple uses li-poly for their batteries - a subset of Lithium-Ion - more advanced. I'll let others who know way more about this information than I do post more. I'm just a battery hobbyist. Highly recommend https://batteryuniversity.com - Isidor's book is great too. Though they're finding today that with Tesla batteries that rapid charging isn't as bad as we once thought.

    Good luck. Batteries are a hobby of mine and I find it difficult to get exact information - especially with the changes in the last 5 years. They handle heat a lot better these days and don't get harmed by keeping at a high charge percentage for long periods of time.
     

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5 October 9, 2018