[HWTest]

I have charged my X3 with a USB 5V 1A charger but I thought it isn't fast enough, so I bought a 5V 2.1A charger.
The problem is the 2.1A charger doesn't charge any faster than the 1A charger.
It took over 6 hours to fully charge from an (almost) flat battery but according to the manual with a 1.5A (or above) rated charger it should took 4 hours (forced shutdown charging).
How does the X3 detect how much current it can draw?
Is it using the USB "data" pins 2 - 3 for detection?
Did I buy the wrong charger?
What could be the problem problem?
 
The 1A charger has the USB pins 2-3 shorted.
The 2.1A charger has 54 kOhm resistance between the pins 2-3.

 

[ClassicalViola]

  I have charged my X3 with a USB 5V 1A charger but I thought it isn't fast enough, so I bought a 5V 2.1A charger.
The problem is the 2.1A charger doesn't charge any faster than the 1A charger.
It took over 6 hours to fully charge from an (almost) flat battery but according to the manual with a 1.5A (or above) rated charger it should took 4 hours (forced shutdown charging).
How does the X3 detect how much current it can draw?
Is it using the USB "data" pins 2 - 3 for detection?
Did I buy the wrong charger?
What could be the problem problem?
 
The 1A charger has the USB pins 2-3 shorted.
The 2.1A charger has 54 kOhm resistance between the pins 2-3.

I'm not sure if your 2.1A charger can be compared to the iPad (3rd generation) charger I use but for me it takes around 3 hours and 45 minutes (a little less than 4 hours) to charge from almost flat to full. I assume that it is almost flat when the X3 does not have enough battery to play for more than a few seconds. I use my the X3 stock USB cable with my iPad charger which says 5.1V and 2.1A. Is your charger similar to an iPad charger and are you using the stock USB cable? (FiiO recommends using an iPad charger with the stock USB cable for best charging results with the X3) Sometimes the type of USB cable also affects charging efficiency.

 

[HWTest]

  I'm not sure if your 2.1A charger can be compared to the iPad (3rd generation) charger I use but for me it takes around 3 hours and 45 minutes (a little less than 4 hours) to charge from almost flat to full. I assume that it is almost flat when the X3 does not have enough battery to play for more than a few seconds. I use my the X3 stock USB cable with my iPad charger which says 5.1V and 2.1A. Is your charger similar to an iPad charger and are you using the stock USB cable? (FiiO recommends using an iPad charger with the stock USB cable for best charging results with the X3) Sometimes the type of USB cable also affects charging efficiency.

I always use the original Fiio cable for charging.
The 2.1A charger was advertised as iPad compatible. I did some research and found out, that the possible current draw is determined by voltages on USB  D+ D- pins (for iPads, iPhones).
 
Mode          D-          D+
1A            2.75V     2V
2A            2V          2.75V 
measured  2.1V       2.8V
 
The measured values are without load, I think they drop a little under load and there should be some tolerance, so it seems to be OK (according to the Apple "standard").
The question is, how is the X3 detecting the max. current it can draw?
 
 
PS On the 1A charger the voltage on both pins (D+ D-) is 3.1V ....

 

[giorgio09]

I bought the Fiio X3 some weeks ago.
 
In this days, since the usb charging (connected to the laptop ) was too much long (7 hours ) I decided to buy a charger .
On the X3 user guide I read that they suggest to buy an Apple original charger.
They say "This can achieve the best charging effect " .
I am writing to say this is not true .
Yesterday in one supermarket I bought this => http://www.brack.ch/belkin-micro-home-charger-259932 for half price compared to an original Apple charger
Dispite it is 5V but only 1A (Fiio recommends 1,5 A or above ) it charged the empty battery in 3 hours and 52 min 
 
So, if you need a charger for your Fiio, don t make thousands thoughts about which is the better 

 
Buy any one and have fun

 

[HWTest]

  So, if you need a charger for your Fiio, don t make thousands thoughts about which is the better 

 
Buy any one and have fun

 That's what I thought but reality differs ...

 

[ClieOS]

There are a lot of USB charger out there with false rating btw, especially those from lesser known brands. So I won't be too surprised if your 2A charger isn't actually up to par.

 

[giorgio09]

   That's what I thought but reality differs ...

uhmmm
 
what do you mean ? 

 

[HWTest]

  uhmmm
 
what do you mean ? 

 
I mean I've bought 3 different already (1x1A, 2x2.1A) and none of them is able to charge the X3 from flat in less than 6 hours

 

[HWTest]

  There are a lot of USB charger out there with false rating btw, especially those from lesser known brands. So I won't be too surprised if your 2A charger isn't actually up to par.

 
I know.
 
But the important part of the question is: "How does the X3 detect the capabilities (amperage) of the charger (if it does at all)?"

 

[ClieOS]

I assume X3 just draws as much current as the source can supply. IIRC, there is a chip inside that controls the current uptake and will switch automatically to high current mode when it detects a high current supply, probably by the common method of resistor shorting the D+ and D-.

 

[HWTest]

  I assume X3 just draws as much current as the source can supply. IIRC, there is a chip inside that controls the current uptake and will switch automatically to high current mode when it detects a high current supply, probably by the common method of resistor shorting the D+ and D-.

 
The first method would be pretty dangerous to overload/destroy the charger.
 
The second method - detecting resistance (or voltage) between D+ and D- is OK, but there is a norm for it - to be exact there is USB battery charging specification and then there is the Apple "norm". I would like to know, which one the X3 follows?
 
I've ordered this device
maybe I'll find the problem with the help of it.

 

[giorgio09]

   
I mean I've bought 3 different already (1x1A, 2x2.1A) and none of them is able to charge the X3 from flat in less than 6 hours

 
I don t understand .
I bought the first I saw in a supermarket (1A => paid 20 swiss franc => about 22 $ or 16 Eur ) and it works very good (3 hours and 52 min ) .

 

[ClieOS]

   
The first method would be pretty dangerous to overload/destroy the charger.

 
No it doesn't, unless the charger is extremely poorly made. Most half decent USB charger should have internal limiter so you can't over-draw its max current output. Thus why it is wise to avoid random USB charger in the dollar store.

 

[HWTest]

   
I don t understand .
I bought the first I saw in a supermarket (1A => paid 20 swiss franc => about 22 $ or 16 Eur ) and it works very good (3 hours and 52 min ) .

 
You were lucky, I not.

 

[HWTest]

   
No it doesn't, unless the charger is extremely poorly made. Most half decent USB charger should have internal limiter so you can't over-draw its max current output. Thus why it is wise to avoid random USB charger in the dollar store.

You are right but the "should" is important.
While doing my "homework" on USB charging and chargers, I found websites, which disassembled and tested various brand and noname USB chargers and the quality varied.
So even a brand and relatively expensive charger is not guaranteed quality.
 
 
PS I think there is a good reason, for the signalling how much current a charger can deliver and a properly designed device should use it (the signalling).