Mar 162014

How to charge faster from usb

Most of people have noticed it that when they connect their smartphones to USB outlets of laptop or desktop PCs their phones takes a very long time to charge, sometimes two times as compare to standard AC wall charger.

Lets first understand why it happens –

Generally PCs USB port are not designed to charge a phone or such devices, their only purpose it to provide or power-up such devices when connected to works efficiently like when you connect USB mouse, keyboard or a Data card then necessary power needed will be provided by USB port which is generally maximum 500 mA at 5 volts. But this is means for USB 2.0 ports if you have USB 3.0 ports in your laptop/desktop it can draw up to 900 mA so if you connect your phone with USB 3.0 port you can charge your phone faster.

how to charge faster from USB

Can you charge faster your phone on USB port-

Yes you can, actually your computer USB port can also provide more ampere even upto 1000 mA but your phone OS restrict it at 500 mA to safety of your USB port or computer from overheating or surge that can damage on USB port. Charging current upto 1000 mA does not harm your phone as AC charger already works at 1000 mA.

How to accomplish faster charging through USB Port (How to charge faster from usb) – 

You can check your phone Charging current with some apps like for Samsung mobiles you can download Galaxy Charging Current Android Apps to check the exact current drawn by your phone while charging. If your phone not drawing proper current e.g. 500mA from USB port than may be you need to replace the USB data cable.

Galaxy Charging Current

After rooting of your phone you can accomplish the faster charging using custom kernels that supports higher charging current even more than 1000 mA for both AC charger and USB charger. High current may damage your battery or phone so do not use more than 1200 mA current in these custom kernel settings. In samsung galaxy s3 Boeffla kernel and Boeffla kernel config app can provide you high USB charging.

Boeffla USB Charging Current

If you don’t want to root your device due to warranty or complication that there is an easy solution to accomplish faster charging through USB port that can be done by making a faster charging USB cable by yourself at home.

For this purchase a cheap micro usb cable from or, after this you need some engineering follow these steps –

Cut the cable in between and strip the cable to remove four wires e.g. red, black , white and green. Cable have two end one is USB cable side (Computer side) second is micro usb side that connects to your phone. At micro usb side (phone connector side) twist two wires white and green together to short them. Now connect both cable parts like this – connect  red & black wires together of both ends, keep separated white and green wires at USB connector side. Now from electrical PVC tape insulate all the wires.

Now your fast USB charging cable have been created, the two wires white & green are meant for data and your phone now think that it is connected with AC charger and allow to draw full 1000 mA from USB 2.0 port. Now you can charge your mobile as fast as from AC wall charger this is all about how to charge faster from usb. Remember this cable only meant for charging, for data transfer you will need another healthy cable.

References –

  • These are small cross section cables, typically 0.14, 0.25, 0.35, 0.5 Sizes, with high quality to ensure reliable signal transmission in electronic instruments, sensors, encoders and actuators with operating voltage of less than 50v.