Attend XDA's Second Annual Developer Conference, XDA:DevCon 2014!
5,807,223 Members 42,067 Now Online
XDA Developers Android and Mobile Development Forum

Charging current

Tip us?
 
decmk
Old
(Last edited by decmk; 3rd September 2014 at 05:33 PM.)
#1  
decmk's Avatar
Senior Member - OP
Thanks Meter 73
Posts: 257
Join Date: Jul 2008
Default Charging current

I just tested, and discovered something weird.
When using original HTC charger, and original HTC microUSB cable, the charging current is 1A, but when I use USB extension cable or spare microUSB cable charging current is 0.5A (490mA) using same original HTC charger.
What's wrong with the USB extension cable or spare microUSB cable?

Original charger and original cable


Original charger, original cable through USB extension cable


Original charger spare microUSB cable
(spare microUSB cable is 1.6m long)



HTC ONE M8
 
LenAsh
Old
#2  
LenAsh's Avatar
Forum Moderator
Thanks Meter 1,119
Posts: 2,672
Join Date: Mar 2011
I've moved this to Q and A - more suitable.

To answer your question - and I don't think your ammeter is particularly accurate - a USB port provides up to 0.5A. The Phone should only draw about 450mA (controlled by the phone) to leave a margin.

The mains adaptor will charge at a higher rate (again controlled by the phone) and in your case appears to be about 1A.

Note that the rate of charge from the mains depends on a number of factors - the temperature of the battery, the actual charge of the battery (the rate slows progessively from about 90% upwards and so on.

The Following User Says Thank You to LenAsh For This Useful Post: [ Click to Expand ]
 
decmk
Old
#3  
decmk's Avatar
Senior Member - OP
Thanks Meter 73
Posts: 257
Join Date: Jul 2008
Quote:
Originally Posted by LenAsh View Post
I've moved this to Q and A - more suitable.

To answer your question - and I don't think your ammeter is particularly accurate - a USB port provides up to 0.5A. The Phone should only draw about 450mA (controlled by the phone) to leave a margin.

The mains adaptor will charge at a higher rate (again controlled by the phone) and in your case appears to be about 1A.

Note that the rate of charge from the mains depends on a number of factors - the temperature of the battery, the actual charge of the battery (the rate slows progessively from about 90% upwards and so on.
Thanks for the answer, but I'm always using original HTC charger witch is 1.5A on the output side, only difference is extension USB cable.
When I connect to USB port on the PC always is 0.5A no matter what cable or extension cable I'm use.
Using extension cable has big difference, i don't know what the clue?

HTC ONE M8
 
LenAsh
Old
(Last edited by LenAsh; 3rd September 2014 at 08:11 PM.)
#4  
LenAsh's Avatar
Forum Moderator
Thanks Meter 1,119
Posts: 2,672
Join Date: Mar 2011
The USB port will ONLY supply 450mA - 500mA (0.5A) - no more. It's limited by the USB 2 spec...

The HTC charger can supply UP TO 1.5A. However, the phone will only draw what it needs - in your case about 1A.

You can put a 5A charger on and it will only draw 1A...

EDIT: Just re-read your OP - the issue you have is likely to be related to the way the HTC USB charging cable is wired.

On some phones, when you connect to a USB port, the phone KNOWS it's a USB port due to the wiring. When you connect to a charger, the charger shorts a couple of pins together (or in Apple's case, a resistor) and the phone then KNOWS it's connected to a wall charger. That's how the phone tells you on screen what kind of charging you're doing...

Sounds like HTC use a proprietary cable...

 
decmk
Old
#5  
decmk's Avatar
Senior Member - OP
Thanks Meter 73
Posts: 257
Join Date: Jul 2008
Probably the phone is detecting voltage.
When I use short cable 25 cm or original microUSB cable voltage is 5.05V, with extended cable is little below 5V (4.95V) and then phone is changing with only 0.5A (490mA).

HTC ONE M8
 
decmk
Old
#6  
decmk's Avatar
Senior Member - OP
Thanks Meter 73
Posts: 257
Join Date: Jul 2008
Or proprietary cable.

HTC ONE M8
 
LenAsh
Old
#7  
LenAsh's Avatar
Forum Moderator
Thanks Meter 1,119
Posts: 2,672
Join Date: Mar 2011
Quote:
Originally Posted by decmk View Post
Or proprietary cable.

HTC ONE M8
That's the most likely. Bad HTC....!

The voltage is not the issue - it can be anything from 4.75V to 5.25V without problem.


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Play Music on Android Wear with Stellio Music Player

Android Wear smartwatchesare growing inpopularity every day. Some devices have already … more

Schedule is up for xda:devcon ’14

With xda:devcon ’14 just around the corner, and the venue close to selling out, there is a lot … more

aLogcat Returns Thanks to XDA Love

The developers of Android, that is Google, gave users several great debugging tools that can be used in … more

And the Winners in the XDA Pebble Development Challenge Are…

Almost two months ago, we set out with Pebble to findthree amazing … more