Qi Wireless Power Charger Heating Nexus to 116 F - Stop Using it?

[Peter Rokkos]

Picked up an inexpensive Qi Wireless Charger on eBay for under $10 - but have noticed a number of problems since I started using it.

The slim Ringke case which I have been using allows the charge to go through but seems to make it a bit finicky on being in the right position to work. Simply bumping my desk will seemingly knock it off resulting in no charge next AM.

More importantly the Nexus gets incredibly hot while charging. I've seen it get to 116 F and seen an overheating notification. Not certain if its the case or not that is the problem - plan on trying it without the case but was trying to see:

-What temperature does the Nexus hit using a Google or more reputable wireless charger?

-116 F seems far too hot and likely doing long term damage; stop using it right?

Thanks.

 

[PPP mcleod2]

I've notice some heat when chasing via wireless but have not put a temperature reader on it.

I've also noticed the heat stops once the phone becomes fully charged.

I will check and see when I use next. What did you use to gauge the temperature?

Posted via Android Central App

 

[bjrosen]

I ahve several Qi chargers and I've never encoutered a heating problem with any of them.

 

[Shilohcane]

I just downloaded this Cpu Temperature App from the Playstore. Changed the app to display in Fahrenheit. I will test it on my Luga Lake Qi charger with and without a case. However my Nexus 5 without a case running normally without charging shows the CPU is between 102F to 107F without charging and the CPU is running at between 7% to 18%. Battery is showing 89F Temperature now without changing and no case on the phone.

Let me get some data. I don't think 116 F is a issue but I don't know if you are talking about the CPU or the Battery Temp. Why don't you download a App and talk both CPU or the Battery Temp. Also this App has a tab for Charging Curve with Temp.

I have read this about a Nexus 5 but I have no idea if the guy knows what he is talking about;

Charging is disabled if the phone gets too hot. 110-120f is the charging cutoff for most phones. 130f is the thermal cutoff where everything powers down. 140f is where bad news begins and the battery will start to bulge and potentially go into thermal runaway. (fire)

The main thing that gets bothered by heat is the battery. 90-100f won't ruin anything, but heat and time are the two main factors in the gradual decline of charge capacity so while "very warm" is not bad, it's not ideal either.

TL;DR: Not a huge deal, but batteries prefer to be kept cool.
Heat with wireless charger? : Nexus5

 

[Peter Rokkos]

I've been using DU Battery Saver and it indicated the 116 F temperature during charging. If I recall, it cut off charging when it hit the 116 temp. At the time I actually downloaded a couple of lock screen apps that allowed the temperature and charge strength to run while charging. They both indicated the same thing, normal charging strength but cut off when it hits a temperature.

I just downloaded CPU Temperature App and will give that a shot as well.

My concern is both short term in damaging the phone, as well as long term diminished capacity over time, although that is a less concern because I typically replace a phone after a year or so on eBay.

 

[Shilohcane]

My Nexus 5 battery was about 72% full when I started this Qi charging test. My house temp is set at 77F. Took off my case on my N5 and used the App above to get some reading without charging or in a case plus just my normal Apps running on my N5 in background. The App showed my N5 was running normal with the CPU is between 102F to 107F ( seems to bounce when some Apps are running ) without charging and the CPU is running at between 7% to 18% background Apps. Battery is showing 89F Temperature now without changing and no case on the phone. That is my baseline for basic operation.

Now put it on my Luga Lake Qi wireless charger.

After 10 minutes saw CPU was at 112F-116F (still bouncing between Temps as Apps were running on the N5) and Battery was at 95F.

After 15 minutes saw CPU was at 117F and battery was at 96F.

After 22 minutes saw CPU was at 107F and battery was at 91 F. Note N5 showed only 96% charged.

Temp App has a tab at the top that shows the "Charging Curve". That showed that after CPU 118F must have gone to 119F the Nexus 5 must have shut off charging or when the N5's battery hit 96% and Temps all dropped on the history charts. Qi charger was still on since the Luga Lake will stay on if running on internal battery inside the Qi charger. Note if it was pluged into the wall I have read it will shut down all the lights on the Luga Lake and turn off. Plugged the Luga Lake into the house power but when I put a cool N5 back on the Qi charger at 96% full the N5 would not give me the connection sound alert of it allowing charging.

This is my Qi Wireless charger.

https://www.youtube.com/watch?v=7xutTrB5J4E

 

[mclasser]

Although I don't have a wireless charger for my N5, high charging temperatures seem to be a common complaint with them.

Sent from my Nexus 5 via Android Central App

 

[Shilohcane]

Although I don't have a wireless charger for my N5, high charging temperatures seem to be a common complaint with them.

Well IMHO after after doing this test today there are zero issues with me for wireless Qi charging. Today when I used that Temp App while I was using my Qi charger it never got past a CPU temp of 118F and battery temp of 96F maximum.

I just left the Temp App running on the scrip over time as I played 10 minutes of a game called Clash of Clans and the Nexus 5 CPU temp was 128.7F and the battery temp was 100F. Both of which were higher than at any point using my Qi Charger. If you are going to worry about a quality Qi Charger over heating your Nexus 5 then you should NEVER use your phone for any games or surfing the internet since from my testing both the CPU and Battery gets a lot hotter after several minutes doing that stuff than when it is on the Qi Charger.

 

[crxssi]

* QI charging will always be a higher temp than cable charging.
* I have been using QI charging since I got the N5 and have never had an overtemp warning and it works quite well.
* I can only speak to the PowerBot charger, which seems to work well, even with my thin Diztronic case.
* I also very rarely have positioning problems and bumping my desk NEVER upsets the charging with my setup.
* Theoretically QI charging will get hotter the thicker the case, because the charging is less efficient and there is more insulation to hold the heat and it will also take longer to charge, which is also more heat for longer.
* Theoretically if the phone is not positioned well, it can cause the temp to increase due to inefficiency.
* There seems to be wild fluctuations between brands of chargers. Although they should all adhere to the QI standard, there might be real differences between the chargers... so you can't judge all QI or Nexus 5 charging based on a single model/brand of charger.
* The amount of heat on any charger (QI, cable, any brand) will vary depending on the charging rate- when the battery is low, I believe it will pull more current and heat will be higher than when the battery is more full and it charges at a lower rate. My battery is rarely below 70% when I am around a charger and slap it on it.
* From near empty, charging the first 80% of Lithium batteries is fast. But the last 20% can take as long or longer than the first 80%. This is why you often see charge speeds listed for 80% and 100% separately in marketing specs.

 

[Shilohcane]

I have been playing with that Cpu Temperature App made by mooncakes. I put my Nexus 5 back into it's Caselogic case and charged it with my original N5 wired charge. This game I am using eats the battery fast. With the case on my N5 using the original N5 charger the battery temp reached 100F which is just a little higher than it did with the wireless charger but with no case on the N5. However the CPU temp was lower this time with the wired chager but that could be because I had the screen turned off this time. With the wireless charger going I had the screen turned on so I could read the Cpu Temperature App. The Cpu Temperature App has a excellent graph that shows temp over the last 20 minutes so you don't really have to look with the screen on to see when it gets hot. However the battery temp is only on the bottom of the main screen of the app.

One thing is clear as day that when you play games with your N5's screen on it gets much hotter much faster than with either a wired or wireless Qi charger. That includes both the temp of the battery and the temp of the CPU.


-

 

[Peter Rokkos]

Really appreciate the feedback and effort from everyone here. I had not been using the CPU Temp App and its a little different than what I had seen before. I didn't even realize there is a separate temp for the CPU and for the Battery. I'm not exactly sure what the DU Battery Saver app was measuring, my guess is its the battery but not certain.

Just did a full charge using the cord from about 30% and the battery never got much higher than 95, but the CPU was definitely in the 120-125 range. Will try tonight and see what the wireless charging does.

I agree with some posters here that screen and gaming definitely heat up the CPU. Google Maps with GPS on also seems to me to really heat up the back to the touch, but that could be because the screen is on for the length of a drive, more than the processing involving.

 

[simplemark1]

The overheating may have something to do with the location of the charge receiver in the phone. My Itian K8 wireless charger has this warning (cryptic english and all...):

"For QI devices,the center of phone need to align with transmitter.
For LG G3,G2,Nexus4,Nokia 920,The receiver is down off the center about 20mm,so your need to put your phone up the center about 20mm.When the phone align the transmitter,the indicator in the corner will become green.
If there is a case with qi phone,Pls note:The thickness of case can't exceed 5mm.And the center of back case can't be metal material. "