Note 2 charging: maximum 0.83 amp phone ON, 0.74 amp phone OFF

[RL in Florida]

so i bought one of these
Amazon.com: Micro SATA Cables - PC USB 2.0 Cable Device Voltage Current Meter Tester: Electronics

and did some tests....with phone ON and phone OFF with various chargers i had lying around.

Here are the results.
I don't have the technical expertise to explain the results, but can assure you i tested each result at least five times to provide an accurate number. I am not going to report exact voltages here, but they range between 4.755 to 5.120. I think amps are the more interesting number:

Fairly controlled conditions. Phone at 50% battery. When on, all antennas turned off (GSM, GPS, WiFi). Screen Off.

The numbers are amperage/amps drawn:



Samsung Note 2 OEM 2A charger (white charger and cable in the box)
Phone ON: 0.83 amps
Phone OFF: 0.74 amps





Samsung OEM 700 mAmp charger (comes with the OEM charger stand)
Phone ON: 0.65 amps
Phone OFF: 0.55 amps





Anker Astro2 Portable USB Charger (Astro fully charged)
Amazon.com: [Upgraded Version] Anker

 

[PiscesCloud]

Hi RL in Florida

Thank you for a very interesting post; I

 

[N6EAJ]

so i bought one of these
Amazon.com: Micro SATA Cables - PC USB 2.0 Cable Device Voltage Current Meter Tester: Electronics

and did some tests....with phone ON and phone OFF with various chargers i had lying around.

Here are the results.
I don't have the technical expertise to explain the results, but can assure you i tested each result at least five times to provide an accurate number. I am not going to report exact voltages here, but they range between 4.755 to 5.120. I think amps are the more interesting number:

Fairly controlled conditions. Phone at 50% battery. When on, all antennas turned off (GSM, GPS, WiFi). Screen Off.

The numbers are amperage/amps drawn:

Samsung Note 2 OEM 2A charger (white charger and cable in the box)
Phone ON: 0.83 amps
Phone OFF: 0.74 amps...........................................

I wonder if that USB cable/meter messes with the D+ and D- lines from the charger. I did a similar test using a cut apart cable (ground, D+, and D- were soldered back together and I put an ammeter in series with the +5V wire). Conditions were similar (48% charge level, phone on with data connection, screen off).
For the stock 2A Samsung charger I got Current=1.64A, V= 4.93V, Power = 8.1W. I got very similar results with a HP Touchpad charger. If the Data+ and Data- lines are not right, the Note 2 (and most other phones) won't draw full current.

 

[RL in Florida]

I wonder if that USB cable/meter messes with the D+ and D- lines from the charger. I did a similar test using a cut apart cable (ground, D+, and D- were soldered back together and I put an ammeter in series with the +5V wire). Conditions were similar (48% charge level, phone on with data connection, screen off).
For the stock 2A Samsung charger I got Current=1.64A, V= 4.93V, Power = 8.1W. I got very similar results with a HP Touchpad charger. If the Data+ and Data- lines are not right, the Note 2 (and most other phones) won't draw full current.

I was thinking it was a D+ D- issue as well, but the samsung 2amp charger is already shorted out internally. (I checked by using a ohmeter and a cut usb cable. There is no resistance between the data wires)

I would think that a D+ D- short anywhere in the line would still measure as a short at the phone end.

Also, if the phone senses a computer USB port, the current would be limited to 500mA.

I agree with you though, that maybe the USB ammeter is off somehow. I might try to use a multimeter like you did. Can you describe your multimeter setup for me in more detail?

 

[Dieben]

I wonder if that USB cable/meter messes with the D+ and D- lines from the charger. . . If the Data+ and Data- lines are not right, the Note 2 (and most other phones) won't draw full current.

Yes, on a charger cable the D+ and D- data conductors should be shorted together so that the device being charged knows that it is connected to a charger, not to a USB port on a computer. Knowing that it is connected to a charger the device being charged will draw full power.

If the device being charged senses functional D+ and D- data conductors it assumes that it is connected to a USB port such as a USB port on a computer and only draws 0.5 (?) amps.

 

[N6EAJ]

I was thinking it was a D+ D- issue as well, but the samsung 2amp charger is already shorted out internally. (I checked by using a ohmeter and a cut usb cable. There is no resistance between the data wires)

I would think that a D+ D- short anywhere in the line would still measure as a short at the phone end.

Also, if the phone senses a computer USB port, the current would be limited to 500mA.

I agree with you though, that maybe the USB ammeter is off somehow. I might try to use a multimeter like you did. Can you describe your multimeter setup for me in more detail?

A short anywhere between the D+ and D- lines would show up as a short anywhere on a continuous cable, but I wonder if the cable/meter you are using from Amazon passes the D+ and D- lines through (without altering their connection or voltage levels). Can you use your cut USB cable to check to see if D+ and D- are shorted after passing through your cable/meter?

My cut cable is has all the wires soldered back together except for the 5V wire. I insert a current meter (a Fluke 189 set to the 10A current mode) into the 5V wire (clip one test lead of the meter on to each open end of the 5V wires). To measure voltage, I use another meter measuring across the 5V wire and ground (after the current meter so I get the actual voltage that the phone "sees"). Like you said originally, the voltage isn't nearly as interesting as the current, but lets me calculate power into the phone (P = voltage * current). The Touchpad charger was less current (1.55A), but higher voltage (5.16V) which gave 8.0W (almost the same amount as the Samsung 2A charger).