enter image description hereI've noticed that recently, USB wall chargers have gotten better, a lot better. While charging my old Nexus One used to take a long, long time, my brand new Samsung Galaxy S3 charges extremely fast, despite having a much larger battery.

Upon examining the USB cable, I noticed that there were two prongs that I hadn't seen before and I supposed that this was part of the reason behind this new, welcome change.

The only question I have now is if I can get a car charger utilizing these new cables enabling me to charge my phone in the car much more rapidly. I travel a lot, and usually upon landing, I'll need navigation in the rental car, which, as I have found, doesn't work if your phone's dead. Do these new, ultra-fast chargers exist for use in the car?

  • the galaxy s3 and nexus one have the exact same cable. – BroScience Oct 5 '12 at 20:36

The two prongs in your picture are just grounding prongs. Most likely, your faster charger is actually a higher-wattage charger, capable of delivering 1A or more of current.

Typically, these chargers also short the USB data wires together using a wire or resistor. This way, the device can detect that it cannot transmit data but may be able to draw up to 1.8A if the charger is capable of supplying it.

There are, indeed, 1A and higher "rapid" car chargers available.

  • Many cheap car chargers SUCK. I've had one that would barely top a few % on the charge in an hour! Now I've got one that 100%s my stuff in 30 minutes. – sinni800 Jan 30 '14 at 7:38

In this cases, the speed of charging not only depends on the device or the battery, or the USB cable, but in the charger itself. The higher the current the charger delivers, the faster the charging will be. The current is measured in Amperes, in small devices you'll find miliamperes. That is, a 650 mA charger, is a 0.65 A. SO, if you want faster charging, simply try with a higher Ampere output charger.

BUT be aware, that higher amperage means higher current, and that generates more heat. and if your device can't handle it, it can literally burn. So, as long as you don't overload it, its good to go.

I'll give you a personal example. I have an old Xperia X8 phone, which charger gives 850 mA of output current. The phone charges fully in about 1 and a half hour (give or take). Once, i was running out of battery at work, and a coworker lend me his charger, made for a tablet, which outputs 2A ( 2000 mA) of current. since most chargers now have an standard micro usb plug, i could use it without a problem. My surprise was when the phone charged completely in just 20 minutes!

As for your question regarding the cable, in has very little (if not nothing) to do with the charging speed. And the prongs have absolutely nothing to do with it. They are there just for letting the cable "snap" into the phone and don't unplug by itself by accident.

Just use the cable that comes with the high current output charger, and you are good. If you use a different cable with the same car charger, you will not notice any significant difference.

NOTICE. I am not responsible if you damage your devices by connecting non standard chargers, be sure your devices can handle the current, and, as long as you detect overheating, better disconnect it!

Hope it helps!

P.S. Sorry if my English is not as good.

  • Any properly designed device is capable of regulating its charge rate to protect the battery and supporting logic. Because of this charging a device with a high-power charger of the correct voltage (e.g. all USB chargers supply 5V) should never result in damage to your device. – bgamari May 22 '15 at 14:26

As with the other replies, it is more likely the charger than the cable.

I assume that car chargers tend to tend to supply less current than wall chargers; the car chargers I have used charge my phone more slowly than a wall charger -- with the GPS running it may not charge at all or very slowly.

If you are doing a lot of traveling, I would suggest purchasing one or two extra batteries for your phone, along with a wall charger. That way you will never be "caught short", so to speak.

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