Help car charger charging in usb mode!

[wrapkgb]

I've searched and searched but still cannot find a precise answer. I bought a powerjolt 2.1 amp car charger from amazon, since I've had it I've noticed it takes forever for the phone to charge! (37% to 67% in 2 hours and it was on stand-by the entire time) So after doing some research I found that the phone is charging in usb mode which has a max of 500ma. So my question is, could this be fixed with a different usb cord? Or is there a way to force the phone while charging, to "ac" vs "usb"? I have also tried a friends 1amp belkin charger with the same result. And I have used the stock usb cable and 2 different aftermarket cables. Im clueless at this point! I did just buy a charge only usb cable from amazon.. not sure if that will make a difference or not since it doesn't transfer data. Anyway any help would be much appreciated! Thanks in advance!

 

[sitlet]

the cable doesnt make a difference, the power source is the problem here.

 

[wrapkgb]

Well thats not what i wanted to hear! Lol. Atleast the cable was only 3 bucks! I just don't get why certain chargers do this. Frustrating!

 

[schwinn]

Late response, I know... but the reason probably is that many phones (my Moto Droid and many CrApple products) require that the data lines on the USB connector are shorted, or at some specific resistance. Many chargers don't do this, so they aren't allowed to charge at full power. It's friggen annoying, but a fact.

I have 2 chargers - one has an "open circuit" on the data lines. This one sets my Droid into "USB" charger mode. The other charger has 53kohms between the data lines (it's a charger designed for CrApple products). This one sets the Droid into "AC" charger mode.

You can see the mode in Spare Parts (app) / Battery Information.

Your EVO probably has a similar "feature".

Apple charger issues can be found here, for example: Slashdot Apple Story | Hardware Hackers Reveal Apple's Charger Secrets

Keep in mind, the OP posted saying that these devices are capable of charging at higher currents. Not all chargers are designed to do so, so just shorting the data lines could damage the charger (and potentially the phone)... just something to be aware of. In theory, if the charger is made "properly" with this in mind, it should have the proper shorting in place as well as the capacity to charge at higher rates.