Charging: USB and AC differences

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  1. iynCognito

    iynCognito Well-Known Member


  2. mecanician

    mecanician Member

    Hi Everyone
    I have been following this thread with interest because I bought a car charger off ebay for
    Hectic Glenn likes this.
  3. mecanician

    mecanician Member

  4. mecanician

    mecanician Member

  5. Newth

    Newth Well-Known Member

    I don't think that's quite right.

    The phone needs to see the pins shorted out, it doesn't matter if it's the lead or the charger or both.

    As long as the pins are shorted, the phone presumes it's connected to a power supply that can do more than 500mA. If it sees the pins shorted, it will say AC charge, no matter what it is plugged into.
  6. Newth

    Newth Well-Known Member

    I think you have this right, but I'm going to slightly edit that......

    To get the HI charge rate in the car,

    AC, 1AMP, whatever you want to call it then the DATA LINES MUST BE SHORTED SOMEWHERE!!!!! The AC charging will be indicated on the phone.
  7. hainman

    hainman Well-Known Member

    thats correct.i use the large pin nokia charger(its a few years old think its for a nokia 3330 or that era) and the 3.5mm large pin to micro usb charger only the one i have is the original nokia product(it has both large and small pin connectors)its def worth a try if it means you get a proper charge and it lets you use the in-phone sat-nav!good luck on your search mate,hail hail:D
    iynCognito likes this.
  8. shmicky

    shmicky Member

    IS it true that when the phone says its Charging (AC) its drawing 1A hence charging faster, but when it says Charging (USB) its drawing less than 1A?
  9. jabtas

    jabtas Well-Known Member

    Just checked my car charger, as supplied in the car kit I posted above

    It also registers as AC charging, it has a sticker on side saying 'for 6800', so I'm assuming also a Nokia charger
  10. hainman

    hainman Well-Known Member

    this is what im using,

    Attached Files:

  11. marshalex

    marshalex Well-Known Member

    the cheap generic car charger i got with my desire screen mount also registers as charging ac! i've made belkin aware of this thread and the issues which have been raised and they're investigating with the product manager if the data pins are shorted on the device or not. should have an update soon!
  12. me too

    me too Member

    Hi guys, I've been lurking around this forum for a week or so since getting my HTC Desire, and thought I'd like to add my two-penn'orth.
    I would caution against putting a short in the USB cable as these wires are used for data transmission eg synch'ing the phone to PC.
    Any charger designed & intended to deliver more than 500mA will (OK - should) already have the output terminals shorted to signal to the phone that it is not connected to a standard USB port (thus limited to 500mA O/P) and can safely draw more current to charge more quickly.
    This shortcircuit in the charger is easy enough to check with a meter, but adding a short will not magically convert a low power charger into a high power one.
    PS anyone without a meter - they're available form Maplins less than a tenner, so much cheaper than a new phone.
  13. robnoble

    robnoble Member

    Apologies for the slow reply - I forgot to subscribe to the thread...

    Correct - it's those two centre points that you've marked in red. I shorted them with a blob of solder.

    JuicePlotter shows battery charging during Navigation, including when playing music (from the phone's speaker - ugh!) at the same time.

    Not the same road route as when I had the original problem though. That could make a difference, due to different signal conditions.
  14. robnoble

    robnoble Member

    I also have one of those chargers, which came with a car mount from an Ebay seller (maybe the same one as yours).

    The Data lines are shorted together inside the MicroUSB plug. If you look (very!) closely, you can see four (easily breakable) lugs holding the plug casing together...

    This is what causes the Desire to switch to AC charging mode, in which it will try to pull > 500ma from the charger.

    The output voltage range specified is quite alarming. I didn't want to risk pumping 10V into my Desire so I'm not using this charger.
  15. Casual Pete

    Casual Pete Well-Known Member

    Just to let you all know the official 1A HTC car charger shows as "charging (ac)"

    The model number is CC C200 for anyone that's interested.
  16. mstanbrook

    mstanbrook New Member

    Some more information:

    The Desire comes with a free car-charger from T-Mobile (UK). This is a complete lead, 12V to micro-usb. Using this charger the phone registers as charging on AC but the rate of recharge is not great. I haven't measured it precisely but roughly with the phone idle it is charging at 15-20% per hour. With GPS on to run Google Maps with voice directions it drains the battery slowly but steadily.

    Using the supplied USB lead plugged in to a PC the phone charges at less than 10% per hour.

    Using the supplied USB lead plugged into the AC Adaptor in a 220V socket the phone recharges at around 50% per hour.

    I purchased one of the Belkin 1A Car Charger converters but, using the same cable as above, the phone only detects it as 'charging USB' and it recharges no faster than a PC connection. I guess I'll send it back.
  17. jimdriver2

    jimdriver2 Well-Known Member

    Sorry should have put the link in before. I bought this one:
    HTC Bravo Legend HD Mini Desire Nexus One CAR CHARGER on eBay (end time 21-May-10 00:11:02 BST)

    Tried it out today on way home with Google Navigate running. It worked perfectly and gained 10% charger turning the 30 min trip! Very pleased.

    One small downside is that it was a little loose in my car's electric port, and if I knocked it (changing gears) it popped out a little. That could be due more to the car though, my vodafone ones for my older phones did the same thing.
    iynCognito likes this.
  18. nx1977

    nx1977 Well-Known Member

  19. iynCognito

    iynCognito Well-Known Member

  20. hainman

    hainman Well-Known Member

    thats the very addaptor i have connected to a large pin nokia in-car charger.pinched it of my wifes a treat.:D
  21. Newth

    Newth Well-Known Member

    Nearly. Providing the charger it's connected to is up to the job, it will try to take more current if in AC mode. In USB mode, it will only take up to 500mA, hence why some car chargers are struggling even if they are rated at 1A.
  22. wisewood

    wisewood Active Member

    I've had to buy a car charger this week in an emergency, had an interview to go to, was stuck in traffic for ages so was running late. Phone dead so couldnt ring ahead and say i was on way etc.

    Spotted carphonewarehouse... went in, bought a generic in car micro usb charger. The phone treats it as an AC supply, not USB.
  23. RobDickson

    RobDickson Well-Known Member

    Quite expensive for a charger, and I don't like Carphone Warehouse. But, as you say, if it works, then it's money well spent.


  24. wisewood

    wisewood Active Member

    Yeah ideally i wouldnt have wanted to fork out
  25. garym

    garym Member

    Any reason I wouldn't be able to use a 2 amp TomTom car charger with a mini to micro adapter?

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