TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

Be cautious of wireless chargers and their impact on your phone’s battery

Discussion in 'Off Topic' started by pdx_m3s, Oct 4, 2019.

  1. pdx_m3s

    pdx_m3s Active Member

    Joined:
    May 18, 2019
    Messages:
    1,118
    Location:
    Portland, OR
    Wireless chargers are convenient (albeit slow), but be aware of the risks (to your phone battery).

    The reason they are slower compared to corded charging is due to their overall inefficiency. All of that wasted power is converted to heat and dumped pretty much directly into your phone Li-ion battery. They WILL degrade your phones battery faster, especially during summer. Don’t just take it from me, research the issue on your own.

    My iPhone 8 (less than 1 year old) degraded 5%, from 97% to 92%, over the course of a couple months using a wireless charger. I noticed the phone was getting warm and finally put 2 and 2 together. Degradation stopped as soon as I switched back to corded charging.
     
    • Informative x 1
    • Like x 1
  2. TyH2009

    TyH2009 Member

    Joined:
    Apr 12, 2019
    Messages:
    504
    Location:
    St. Louis
    I have an iPhone XS Max, had it a little over a year, almost strictly charge wirelessly for about the last 6 months, Jeda in my Model 3 since April and a wireless stand at my desk at work, and I’m still at 100% battery health.
     
    • Like x 2
  3. Nopantz

    Nopantz Member

    Joined:
    Feb 28, 2019
    Messages:
    51
    Location:
    Denver Metro
    I am also at 100% health on my year old iPhone Xr been charged mostly on home and auto wireless.
     
    • Like x 1
  4. pdx_m3s

    pdx_m3s Active Member

    Joined:
    May 18, 2019
    Messages:
    1,118
    Location:
    Portland, OR
    • Informative x 2
  5. pdx_m3s

    pdx_m3s Active Member

    Joined:
    May 18, 2019
    Messages:
    1,118
    Location:
    Portland, OR
    Even the most tortured phones won’t show any degradation on the first 6-8 months. There is a buffer in the “100%” battery health metric provided in iOS.
     
  6. DopeGhoti

    DopeGhoti Active Member

    Joined:
    Aug 28, 2019
    Messages:
    1,129
    Location:
    Phoenix, AZ
    My phone is aware of this, and if the internal temperature gets too high, it disables wireless charging to prevent damage. I found this out because in my previous car, the Qi charging mount was in direct line of sight with the windscreen, and therefore Sol. On a hot afternoon, I would be unable to charge wirelessly. I doubt this will be an issue with the Model 3, because the phone will be tucked away out of the sun, in a car that is always at a comfortable temperature before I get to it.

    The thing that worries me is leaving my phone (and therefore my car key) in the car, as I'm currently used to it being in my pocket when I egress the car. But I suppose it'll be easier to notice that I've not got my phone on my person than a car key, so I have that going for me at least.
     
  7. jmaddr

    jmaddr Member

    Joined:
    Mar 29, 2019
    Messages:
    745
    Location:
    Florida
    Technically this applies wired or wireless. If the phone temp is too hot, all charging is disabled.
     
    • Like x 1
  8. earthwormjim

    earthwormjim Member

    Joined:
    Jun 25, 2019
    Messages:
    165
    Location:
    California
    A 3C rise in phone temperature is nothing. You cause a greater rise having the phone screen on, or just using the phone or holding it. Are you going to tell people not to hold their phones too?

    The degradation that comes from wireless charging is not so much the inefficiency losses, its the fact that your phone is still running entirely off of the battery while charging. Using a wired charger, the phone can run off of the cable itself. In a car though, how much extra battery use time are we really talking about? Maybe an hour for the average driver, per day? Pretty insignificant, and no worse than just not charging at all.

    Where wireless charging can really lead to a significant difference is when using it to charge your phone overnight. Your phone's battery never gets that 8 hour break it normally would with a wired charge cable.
     
  9. pdx_m3s

    pdx_m3s Active Member

    Joined:
    May 18, 2019
    Messages:
    1,118
    Location:
    Portland, OR
    For me, it was far more than a 3C rise.
     
  10. earthwormjim

    earthwormjim Member

    Joined:
    Jun 25, 2019
    Messages:
    165
    Location:
    California
    #10 earthwormjim, Oct 5, 2019
    Last edited: Oct 5, 2019


    Versus a wired charger? Then perhaps you were never aligning your phone with the coil.

    I cannot feel any temperature difference with my wireless charger at home, versus using a wired charger. Same with the charger in my car.

    Perhaps you are comparing with no charger at all? In that case, yes a wireless or wired charger causes a significant temperature rise.

    3C is what the study you linked said for an aligned charger. So that's not valid now?
     
  11. Eno Deb

    Eno Deb Active Member

    Joined:
    Aug 17, 2018
    Messages:
    2,591
    Location:
    SF Bay Area
    This depends on the charging power, and to a lesser extent on good coil alignment. Chargers connected to the car's front USB ports generally charge at 5W and will not produce much heat. The OEM Tesla Qi charger also has oversized coils to improve alignment for phones of different sizes. My iPhone 8 gets barely warm on the charger.
     
  12. DopeGhoti

    DopeGhoti Active Member

    Joined:
    Aug 28, 2019
    Messages:
    1,129
    Location:
    Phoenix, AZ
    Depending on the phone, it may have sufficient granularity to individually disable induction charging independently of traditional charging. Ofttimes, I would, when seeing it not charge wirelessly, go ahead and plug in the USB-C cable and it would be happy as a (n unusually warm) clam.
     
  13. KenC

    KenC Active Member

    Joined:
    Sep 4, 2018
    Messages:
    2,661
    Location:
    Maine
    I use a mix of wired and wireless charging. Wireless during day, and wired overnight. I find the wired charging warms up my iPhone X more than wireless.

    My 2yr old iPhone X shows 98% on battery health, but when I run the CoconutBattery app, it shows 2690mAh out of a design capacity of 2716mAh, so 99%. Cycle count is 240.
     
  14. KenC

    KenC Active Member

    Joined:
    Sep 4, 2018
    Messages:
    2,661
    Location:
    Maine
    What's your cycle count, and did you look at your data from the CoconutBattery app?
     
  15. boriszima

    boriszima Member

    Joined:
    Jul 12, 2018
    Messages:
    646
    Location:
    Los Angeles
    interesting information. I posted this somewhere, my iphone went down to 89% less than a year usage. I mostly use wired charging and only when driving use wireless pad. I think new feature on iphone to charge to 80%or something will improve degradation going forward.
     
  16. jkoya

    jkoya NA2 NSX

    Joined:
    Nov 21, 2018
    Messages:
    3,626
    Location:
    Northern CA
    My iPhone X is 22 months old and charged exclusively with an Anker Wireless charger (bought the Taptes wireless charger for the Model 3, but haven't put my phone on the charger, other than to test it) and my battery health is 99%.

    Never thought about the harm wireless chargers could do, so thanks for the education and insight...
     
  17. ewoodrick

    ewoodrick Well-Known Member

    Joined:
    Apr 13, 2018
    Messages:
    5,283
    Location:
    Buford, GA
    I'm going to have to disagree with this. For the power that makes it to the phone, efficiency is pretty high, very little energy is converted to heat in the phone.

    The loss is in the charging portion. That's what gets warm and while some of its heat is sent to the phone, a lot is sent to the surface that it is setting on.
     

Share This Page

  • About Us

    Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.
  • Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


    SUPPORT TMC