When charging my Samsung Galaxy S4 via the OEM USB port while being used in my Fit (i.e. streaming music), the charging power just is not sufficient to offset the phone being used at the same time, the battery level keeps dropping. Accordingly, I'm just wondering if anyone has any idea what the output is of the OEM USB?? I believe its not a high-power USB but not sure what "high power" is exactly.

The factory Samsung fast charger is 2A 5V....most cigarette lighter chargers output 1A 5V, which appears reasonable but before buying one I'm curious if the OEM USB port provides similar power, if so, the cigarette lighter charger will do nothing for me......i've read that it may only output 500mah 5v.... but not sure.

Thoughts?

 

The usb protocol is 500ma. This is when you're using the usb for actual data. So its correct for the usb port to only output 500ma since it's used for data. Otherwise it may fry things.

You can get a power inverter which often has usb power ports. If it is not enough for you on usb, then inverter to 110v then you can connect your specific charger(s) to the regular 110 plug.

 

Thanks for the quick reply, that's helpful.

 

I too have the Samsung S4 which needs more than 500 mA to keep pace with battery drain while the screen is on, if you're using GPS etc. The solution which works great for me is below, less than $2. Phone easily charges at a good rate and doesn't get hot. Try one, and it has 2 USB charge ports. Just add your own cable and get juiced.
http://www.ebay.com/itm/2-Port-Mini-Universal-Dual-USB-Car-Charger-Adapter-Bullet-5V-2-1A-1A-Black-/380860604516?pt=US_Cell_Phone_PDA_Chargers&hash=item58ad0fa064