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Why not all chargers are the same!!!

bob_loblaw

Newbie
Apr 2, 2010
28
8
After doing some research as to why my some of my 1A usb ac adapters take twice as long as the stock adapter, I've finally found an answer.

All USB adapters have 4 pins: pin 1 supplies the 5V, pins 2 and 3 are data lines, and pin 4 is the gnd. According to the latest charging standard, for a portable device to see 1A, pins 2 and 3 have to be shorted (standard specifies 200 ohms) for the device to allow 1A. If these data lines are not shorted, the phone will just see 500mA, the same as a computer's usb port. This is probably why it will show usb charging as opposed to ac on the phone. Because older devices do not rely on this standard (some ipods for example), chargers oriented for these devices will not work properly.

So, beware the next time you buy a usb charger because there's a chance it won't be any better than charging straight from your computer.

USB Standards via usb.org
 
Unfortunately, I can only think of one way to check, basically with a multimeter.

howarmat, it will actually matter to you depending on the scenario. 500mA charge while running power intensive apps like google nav prob won't charge the battery at all. Also, htc has mentioned before that if the battery drops below 10%, usb charge will not work on the phone.
 
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yes if you are using a ton of apps at the same time you might not be able to keep up with a 500 mA charge rate, but like i said, you need to just look at the mA rating to make sure its not 500 mA and make sure you get something like 1 A instead.

And HTC is false when it says under 10% will not charge the phone as I have done it

Pandora + Navigation software (with GPS) + crappy charger = batter drain
 
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I called HTC trying to order the charger that came with the phone. They put me contact with their parts dept who said all they have available is the universal travel charger cnr5310 for $40. This same charger can be found for ~$5 on amazon. I'd be weary though as I've read pretty bad reviews about the prongs falling off after a little while.
 
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I bought the Verizon car charger. When I have GPS navigation + btunes (music app) running eventually the GPS signal will stop and the incredible's LED will flash back and forth between red and green. I have to turn GPS back on manually, and the LEDs continue to alternately flash. I don't think the battery drains, but it appears to charge extremely slow.

I had the same problem with a griffen car charger and usb cable, but that was actually not giving enough power when all those apps were running, so it was draining the battery.
 
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I bought the Verizon car charger. When I have GPS navigation + btunes (music app) running eventually the GPS signal will stop and the incredible's LED will flash back and forth between red and green. I have to turn GPS back on manually, and the LEDs continue to alternately flash. I don't think the battery drains, but it appears to charge extremely slow.

I had the same problem with a griffen car charger and usb cable, but that was actually not giving enough power when all those apps were running, so it was draining the battery.

I have the vzw car charger too now, and it seems to work fine for me and charges as fast as the stock ac charger. It sounds like your phone may have overheated. I noticed when I was using google nav my phone started getting a little on the warm side of things, guess after extended nav use it could get too hot.
 
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ok so i got a USB charger for my car and it is rated at 1A. but when i plug in my phone it says its a usb charge. (as opposed to when i plug in at home it says AC)
i dont quite understand the OP. what would i need to do to my charger in order for my phone to recognize that it is a 1A charge and not a 500ma??????
im perfectly ok with dismantling and soldering things if needed.

EDIT:
after re-reading the post it sounds like i need to get a 200 ohm resister and attach it to the wires that lead to the D+ and D- connections on the usb cable.
is that right?
 
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Unfortunately I havent had the time to try this out yet. Also i sort of forgot about it. I have been using my home charger along with a car cigarette to 2 prong dc->ac converter. maybe this upcoming week I will look into this again. I did find a car charger that does work correctly as well. A friend of mine has an "i go" setup that has exchangeble tips. I used that in his car and it worked correctly. I will find a link to the site when i am near a computer.


EDIT:
this is the adapter my friend has in his car:
http://www.igo.com/mobile-device-chargers/car-charger/invt/ps002550007/

im thinking of buying this for my car as well. you just need to buy a new tip for it each time you switch to a new standard. it looks to me though that micro-usb is going to be the new standard for several more years just like mini-usb has been the standard for my last 3 cell phones. if i had this during that time i would have just had to buy a new tip (7.49$ plus shipping) right now for my incredible. hopefully if i buy this i wont be changing my tip for awhile, but at least it wont be 20$ each time i switch devices.
 
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This thread is great. I had been thinking to myself why my older 1A USB charger said "USB" and my OEM 1A charger said AC. I thought maybe the older just wasn't meeting the requirements for current anymore, but now I know it's the data pins. Nice. I've got a lot of resisters around and I might mod it. I do electronics work as a profession so it shouldn't be too difficult at all.

Edit: So I did some comparisons.

The only wall charger I have that shows "USB" is a 1A older one that I can't even remember where it came from. I think it was my wife's from before we got married. I'm assuming now that it will only charge at 500mA (which makes sense from experience with it).

I have one that came with an LG bluetooth adapter (0.7A) that has an integrated cord (not just a USB port) and it shows as AC on the Incredible, so I can assume it actually charges at 0.7A.

I have another one that came with my LG EnV Touch. It has the USB port on it and shows as AC on the Incredible, so a full 0.7A (it's rated capacity).

And finally the OEM charger of course shows AC and I can assume it's charging at its rated 1A.
 
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