Device USB Charging Rates and other info

[SethK]

Basically, is there a place that has a listing of all phones (any other devices), and their charging info? Specifically, what I'd be looking for is: what method they use to indicate different chargers (D+/D- shorting, voltage dividers, etc.) and what is the expected currents to be drawn.

For example, I have my Galaxy S3, and I've gotten it to draw about 430mA with the data lines shorted, but that seems like a very small number compared to the battery capacity (7.98Wh, so 1C would be anywhere from 1.9A to 2.1A).

Thanks in advance.

 

[twister6]

Basically, is there a place that has a listing of all phones (any other devices), and their charging info? Specifically, what I'd be looking for is: what method they use to indicate different chargers (D+/D- shorting, voltage dividers, etc.) and what is the expected currents to be drawn.

For example, I have my Galaxy S3, and I've gotten it to draw about 430mA with the data lines shorted, but that seems like a very small number compared to the battery capacity (7.98Wh, so 1C would be anywhere from 1.9A to 2.1A).

Thanks in advance.

How did you measure that current, using free Galaxy Charging app or some other way? Btw, I just reviewed a really cool gadget to measure current/voltage from your wall or car charger, you might find that useful: http://androidforums.com/samsung-ga...r-charging-your-phone-tablet-w-lots-pics.html

 

[SethK]

I'm using a benchtop power supply to measure the current (set to 5VDC and current limiting set to 3A).

And thanks for product link. I'll be buying two soon.

 

[chanchan05]

Because a USB port can only give about 500mA approximately? You really can't go much higher than that. Unless you got one of those cables where you connect to two USB ports to the phone.

 

[SethK]

I'm not plugged into the USB port on my computer. I'm plugged into the benchtop supply itself, which can supply 3000mA (3A) and is what I'm using to measure the current being delivered.

 

[twister6]

I'm not plugged into the USB port on my computer. I'm plugged into the benchtop supply itself, which can supply 3000mA (3A) and is what I'm using to measure the current being delivered.

Btw for bench top supply in this case you really don't need to set overload current limit. As you aware, the phone will not sink more current then it needs, and I think S3 is limited to 1A, right? I wouldn't expect any inrush or spikes at start up

With that voltage usb in my link, I will have to find some time and modify it with micro-usb male/female connectors. Now that would be totally useful to measure the current draw through entire charger/cable path.

 

[SethK]

Actually, I stated the current overload limit just to eliminate that as a possible source of the reduced current.

You're right that the phone would not sink any more current than it needs, which is why I'm making it a point of draining my phone significantly (to between 30-50%) before charging it. However, even with the battery depleted that far, the charging current just doesn't cross 500mA, which is what bothers me. My old DroidX used to take 1.7A when the battery was below 70%, which would charge the battery rather quickly, and why I'm surprised that the Galaxy doesn't take any more current than it does.