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Why not all chargers are the same!!!

Discussion in 'Android Devices' started by bob_loblaw, May 26, 2010.

  1. bob_loblaw

    bob_loblaw Newbie
    Thread Starter

    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

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    INTREPID-NY Android Enthusiast

    Interesting. Someone was asking this question in another thread.
  3. jayefef

    jayefef Android Enthusiast

    Lets say I'm a dummy in this.... How would I know if the pins are shorted? I've been trying to research car chargers and am totally stumped on which would provide a quick and good charge .
  4. howarmat

    howarmat Android Expert

    i honestly dont think it matters. The higher the mA rating the faster it charges. most advertise that value and its always on the plug also
  5. bob_loblaw

    bob_loblaw Newbie
    Thread Starter

    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.
  6. howarmat

    howarmat Android Expert

    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
  7. bob_loblaw

    bob_loblaw Newbie
    Thread Starter

    howarmat, like I said in the OP even though the manufacturer rates the charger at 1A doesn't mean you will see 1A based on them not following the standard. The OP explains that the phone has detection hardware to verify that the data lines are shorted.
  8. drhill

    drhill Android Expert

    Pandora + Navigation software (with GPS) + crappy charger = batter drain
  9. ctc

    ctc Android Enthusiast

    I can't find a OEM HTC wall charger anywhere. I want a 2nd for work. My LG charger is going at USB speed...slooooow.
  10. bob_loblaw

    bob_loblaw Newbie
    Thread Starter

    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.
  11. sheepforwheat

    sheepforwheat Member

    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.
  12. Outatime

    Outatime Android Expert

    I bought the VZW car charger too (the one without the extra USB slot) and it charges as fast as the one that came with it.
  13. drhill

    drhill Android Expert

    I am using a griffen that I borrowed from work until Seidio finally releases their charging car mount. The griffen is junk.
  14. DroidPower

    DroidPower Android Enthusiast

    the Moto DROID chargers (USB) fit the INCREDIBLE...
  15. terryzx

    terryzx Member

    My old Blackberry Tour one fits it the DI also
  16. howarmat

    howarmat Android Expert

    any microUSB connection will work for the most part. There is legislation trying to make that the standard. i think it is in Europe already
  17. bob_loblaw

    bob_loblaw Newbie
    Thread Starter

    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.
  18. howarmat

    howarmat Android Expert

    yes the phone wont charge then
  19. jasperwill

    jasperwill Android Enthusiast

    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.

    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?
  20. kevin.t

    kevin.t Lurker


    Did you try out your idea? There has to be a way to modify these cigarette lighter plug-in usb adapter/chargers so the phone will see a full 1 amp like in AC charge.
  21. jasperwill

    jasperwill Android Enthusiast

    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.

    this is the adapter my friend has in his car:

    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.
  22. kevin.t

    kevin.t Lurker

    Thanks, I might buy that iGo one for the time being. I wish there was a way to use the usb ones.
  23. sabrewings

    sabrewings Android Expert

    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.
  24. jasperwill

    jasperwill Android Enthusiast

    that would be great! please report back to us what you do and if it works. if you can draw a simple circuit diagram for others to fallow that would be even better.
    i have very very little experience with soldering and electronics so i was worried about damaging my phone if i messed something up.
  25. bob_loblaw

    bob_loblaw Newbie
    Thread Starter


    In case anyone's looking for the original charger that came with the phone, I picked this one up myself.

    HTC OEM Charger

HTC Droid Incredible Forum

The HTC Droid Incredible release date was April 2010. Features and Specs include a 3.7" inch screen, 8MP camera, Snapdragon S1 processor, and 1300mAh battery.

April 2010
Release Date

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