Will a 12W charger shorten the battery lifespan?

Discussion in 'iPhone Accessories' started by AMSOS, Jun 10, 2018.

  1. AMSOS macrumors member

    Nov 21, 2010
    I’ve just got a new iPhone 7 and while I am loving the transfer from Android, the battery backup and charging time are irksome.

    I looked around some and realised that 12W chargers work much better than the 5W one supplied with the phone.

    So I was planning to get the Anker 12W charger -


    instead of the more expensive but not necessarily better quality iPad one.

    However, I wonder if there may not be a method in the madness in the decision to supply a 5W charger? Does this not ensure a much longer lifespan of the battery, especially since a lot of users keep their iPhones for more than 3 years. Or are there other reasons such as cost for this decision?

    So I am wondering if I may end up negatively effecting the lifespan of the phone’s battery by shifting to a 12W charger?

  2. gahig ulo macrumors 6502a

    gahig ulo

    Nov 11, 2017
    riverside california
    Yes.my iphOne 7+ significally reduce its battery health and in my opinion it will drain the battery faster too.
  3. AMSOS thread starter macrumors member

    Nov 21, 2010
    I see. Can you say something more about how you used the 3rd party charger?
    Did you used to take the phone down to 0 or 10% and then charge it to 100% ?
    Or something else?
  4. NoBoMac macrumors 68000

    Jul 1, 2014
    I have been using 12w chargers for years now, and no, not seeing any battery death. I had a 6 for three years, and yes, since it was a 3yo battery it was not what it once was, but, never had to replace the battery.

    Now, my charging is a mishmash. In the morning, plug the phone into a 12w to charge the device while I'm showering, making breakfast, etc. The car has a Lightning cable to the car stereo, which charges (5w) while playing music through that. While at the computer, and the phone is getting low, I'll charge via USB. I bring a 24w 2-port Anker charger with me when I travel (for my iPhone and iPad) So, while I do use 12w, usually, once a day, I'm also charging by other means, so MAYBE, not putting any additional strain on the battery. And I usually never get too low: 20% of less is an odd day where I have not been near a charger all day (generally go to bed with > 50% on the meter).

    Now, remember, the higher watt chargers will go 0 to about 60-65% at full throttle, and then the device will negotiate a slower charge the rest of the way, so, that helps preserve battery.

    Can always have best of both worlds: get the 12w charging for the times you really need it, 5w charging to top off through out the day. Don't let the device get down to zero where 12w charging will be working longer (read: generating longer time spans of extra heat) to get back to a useable level.

    Let's put it this way: Apple supports USB-C charging in their new devices which charges at 18w per test results. If not a conspiracy theorist, Apple seems to believe > 5w charging is ok. And if one believes the rumors, the 2018 phones might be coming with higher watt charger.
  5. AMSOS thread starter macrumors member

    Nov 21, 2010
    I do want to keep using this for the next 3 years so this is quite encouraging!
    I see what you mean and yes this could be a good compromise. In fact, I now try to never let the battery go down to more than 50%. I usually charge up to 75% but for the iPhone it looks like 80% is a better limit - it seems to me the battery comes down quicker from 75 to 70% than it does from 80 to 75%
    Yes, that makes sense. I think for top up charges from 50% to 80% I will use the Anker and if lower than 50% I'll stick to the standard charger.
  6. irod87 macrumors regular

    Jan 25, 2012
    I’ve been using the 12w chargers on all my apple stuff. Never noticed any adverse effects.
  7. BugeyeSTI macrumors 68020


    Aug 19, 2017
    I’ve been using 12 watt iPad charger on all my iPhones and iPads exclusively and after three years, my 6S is at 94% capacity. I’ve been using it on my X along with an Anker powerwave 7.5 watt wireless charger since December and it’s showing 100% capacity. I keep track of battery capacity using Coconut battery...
  8. satinsilverem2 macrumors 6502a


    Nov 12, 2013
    Richmond, VA
    Ive been charging my iPhones and iPads with an Anker charger (2.4amp= 12watt) for years and I haven't noticed any side effects of using it. it charges faster and if it truly harmed the battery then apple wouldn't have supported 12 watt charging to begin with.
  9. AMSOS thread starter macrumors member

    Nov 21, 2010
    Good to hear that! It’s encouraging especially since having come from the newer Android phones I really do want to avail of the benefits of faster charging. I’m not looking for super fast charging but just something that speeds up things a bit. The 5 W brick is pretty much from a different era.
    How true. Now why did I not think of that before?!
    I’ve also been making some tentative experiments by using the Anker power port is elite. This as you will know is not a fast charger but employs their IQ technology. I’ve noticed that it charges my phone (beteeen 40 or 50% to 75 or 80%) noticeably faster than the standard iPhone charger. Best of all I can discern no noticeable heating up of the phone. This I think is crucial for battery health as a battery heating up during charging is a clear indicator negative impact on battery life span.
    I also noticed that when I charge the phone from my MacBook Pro’s USB 3 port it seems to charge even faster and again I discern no significant heat up of the phone.
    So I’m guessing this is just marketing at play and the battery life span is not affected as long as you use a good quality charger and ensure no heat up while charging.

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