Wireless charging cycles between 100% and 99%

[BMWBig6]

Just installed a wireless charging receiver on my Note 3 and it seems to charge fine on my charging pad. The only problem is sometimes it will stop charging, then immediately reconnect (I get the "Wireless charging now active" dialog box). Then a few seconds later, it will do it again. Sometimes it won't do this at all, other times it will repeat this for hours.

Is this happening because the phone is not positioned properly? Or is it because the phone fully charges (to 100%), then it turns off and as power is consumed, it starts charging again (at 99%) until its topped off again?

How do I stop this from happening? Is this a hardware issue, or can I change an Android phone setting? Or would a 3rd party app for battery monitoring help throttle power or control charging cycles?

In case it matters, here is what I'm using:

• White eBay Qi-compatible charging receiver:

​

• TYLT Vu wireless charging cradle:

• Ringke Slim Case:

 

[BMWBig6]

I think I've narrowed it down to the Dock Clock app (a nightstand alarm clock app). When I disable or uninstall it, the phone charges fine. When I have it automatically activate the app when the phone begins charging, the cycling happens. I contacted the developer and he suspects the power draw from the app is pulling more juice than the charger can provide so it suspends charging whenever this limit is exceeded. Does that make any sense? I guess I need to find a different night stand clock app.

 

[Bodycount]

I use the app "Night Clock" and with the helper app "Llama", I have it automatically turn on when I plug my phone in to charge. So I plug my phone in, and the Night Clock app turns on with the current time and my alarms.

When I was using my Droid Razr, I did the same thing with "Smart Actions" and "Razr Dock". But can't use Smart Actions with a Samsung device

 

[BMWBig6]

Thanks for the suggestion, I will look into night clock and my other options. Llama seems interesting in its own right.

 

[Rukbat]

Wireless charging is limited in its ability to supply current. Supplying 2 Amps wirelessly (the Note 3 charges by a USB 3.0 port) would be a bit of a problem. So they probably limit wireless charging to the 2,0 limit of 100mA, which CAN keep a Note 3 at 100% charge, but not with a fairly bright screen and an app that's awake constantly. If it's displaying a changing analog clock it has to wake up once a second. (A digital clock may only wake up once a minute.) That eats a lot of current. An alarm app that goes to sleep and doesn't wake up until the alarm time (meaning it doesn't display a running clock) would use a lot less current.

But what they say makes a little sense. My view is that if the app makes the phone draw, say, 125mA, and the charger can supply only 100mA, there's a 25mA drain on the battery when the clock is running. (Of course if that's constant, the battery will just die later rather than sooner if it's on the charger. There's no way to make a 100mA input exceed a 125mA output - if you can make 1 + 1 = 3, I can make us both the wealthiest [and most famous] people in the galaxy in about a week.)

So if they limit the output current of the charger - IOW, if you short the contacts on the receiver instead of connecting them to a battery, and the charger still only puts out 100mA into the short - there's no reason to cut the charger off when its current capability is exceeded. And limiting the current is trivial, electronically.

That's why there isn't just one engineer in the world, and why we have betting on horse races - peoples' opinions differ. I wouldn't choose the option they did, but I won't say they're wrong - they just think differently than I do.

 

[BMWBig6]

Thanks for the detailed explanation. I may use an app that logs battery charging rate in amps.

 

[big_z]

Wireless charging is limited in its ability to supply current. Supplying 2 Amps wirelessly (the Note 3 charges by a USB 3.0 port) would be a bit of a problem. So they probably limit wireless charging to the 2,0 limit of 100mA, which CAN keep a Note 3 at 100% charge, but not with a fairly bright screen and an app that's awake constantly. If it's displaying a changing analog clock it has to wake up once a second. (A digital clock may only wake up once a minute.) That eats a lot of current. An alarm app that goes to sleep and doesn't wake up until the alarm time (meaning it doesn't display a running clock) would use a lot less current.

But what they say makes a little sense. My view is that if the app makes the phone draw, say, 125mA, and the charger can supply only 100mA, there's a 25mA drain on the battery when the clock is running. (Of course if that's constant, the battery will just die later rather than sooner if it's on the charger. There's no way to make a 100mA input exceed a 125mA output - if you can make 1 + 1 = 3, I can make us both the wealthiest [and most famous] people in the galaxy in about a week.)

So if they limit the output current of the charger - IOW, if you short the contacts on the receiver instead of connecting them to a battery, and the charger still only puts out 100mA into the short - there's no reason to cut the charger off when its current capability is exceeded. And limiting the current is trivial, electronically.

That's why there isn't just one engineer in the world, and why we have betting on horse races - peoples' opinions differ. I wouldn't choose the option they did, but I won't say they're wrong - they just think differently than I do.

When I have plugged in my charging pad to the Samsung 2A OEM wall charger, I have seen charging rates (with the screen off) around 25%/hr. Contrast this with plugging in the OEM charger directly to the phone, which charges about 55-60%/hr (both measured by a widget I have). My guess is that I'm getting around 1A, maybe a little less, on the wireless.

I have a crappy charger (from my HTC Hero) at work that I think is 1A (may be 500mA, dunno, the plug is buried on the floor of my desk and my back's been hurting the past week) and, plugged in, it only charges about 6%/hr. When I hooked it up to the wireless pad it only charged at about 1%/hr. I'm replacing it today with an Anker 5 port charger.

 

[Lee5000]

Here's something worth reading regarding cell phone batteries.


How To Take Care of Your Smartphone Battery the Right Way