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  1. jerrykel's Avatar
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       #1  
    I use a 1 ft. usb cable with the round adapter that came with pre.
    I find it charges 5 to 10 times faster than a 3 or 5 ft. cable. More likely due to less heat loss.
  2. #2  
    please forgive me if I say that I dont believe you, or something else was affecting your test. That would mean the longer cable was dissapating at least 5 to 10 times the power it was transmitting. If that was the case there would be less than a volt at the phone and it woulnt charge at all.

    I suggest you use govnah to measure the charging current.
  3. jerrykel's Avatar
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       #3  
    Govnah show between 370mag to 400mah. Maybe it is not that much , but there is definitely a big difference.
  4. #4  
    hes right. I started using the short cable. Really short, and i see it charging super fast. But then again, it might jusr be my imagination :O
  5. #5  
    If there is truly that much difference between the cords, it would be due almost entirely to quality of the cord, not the length. There is not much loss of current over a few feet in a QUALITY cord.
    I see pandas.
  6. #6  
    Quote Originally Posted by jerrykel View Post
    I use a 1 ft. usb cable with the round adapter that came with pre.
    I find it charges 5 to 10 times faster than a 3 or 5 ft. cable. More likely due to less heat loss.
    As an Electronics Engineer I take exception to this fanciful talk. The only way that is possible is if the long cable is defective.

    The resistance of a 3-5 ft cable is almost negligible. At most there would be a 1-3 % difference in current loss for these distances. Even those numbers are high compared to what it should really be. Again, this is assuming the cable isn't defective.

    Using Govnah or Dr. Battery [both free] you should be able to monitor the charging current.
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  7. #7  
    Considering the conductivity law. You have got a point. THe conductivity is proportional to Length (I am hiding the inverse proportionality part due to negligible cross sectional area.) But i don't think that it would affect the charging 5-10 times faster. Your are right at your point.
    I have experience this with my External USB HDD's. They do work faster with small cables.
    Also, I've experienced it with LAN cables.
    Shorter the cable quicker the transmission.
    Many time i am not able to check my Pm early. PM me your query with your frequently checked email address. Or better way you can mail me at: 'okaymailme@yahoo.in'
  8. #8  
    Agreed for USB cables that their design results in drastic losses compared to power cords.

    However, OP stated "with the round adapter", i.e. power cord. He is getting these results when connected to an outlet, not USB. Thus, e-gadget-guy couldn't have explained it better in layman's terms.
    I see pandas.
  9. #9  
    Which answers the question I just asked myself last night.

    "Why does my phone charge faster plugged into the wall instead of the computer?"

    Thanks, guys. Lol
  10. jerrykel's Avatar
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       #10  
    Do the experiment yourself. May be only twice as fast
    govnah with 1 ft. cable was about 400ma. 5 ft. was 150ma.
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       #11  
    Quote Originally Posted by jerrykel View Post
    Do the experiment yourself. May be only twice as fast
    govnah with 1 ft. cable was about 400ma. 5 ft. was 150ma.
    with 2800mah mugen battery,went from 72% to 100% in 55 min. With 15t. Cable
  12. jerrykel's Avatar
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       #12  
    Quote Originally Posted by jerrykel View Post
    with 2800mah mugen battery,went from 72% to 100% in 55 min. With 15t. Cable
    1 ft. Cable
  13. #13  
    Quote Originally Posted by jerrykel View Post
    Do the experiment yourself. May be only twice as fast
    govnah with 1 ft. cable was about 400ma. 5 ft. was 150ma.

    Read this: http://forums.precentral.net/palm-pr...tone-dock.html

    I think your adaptor or your cables may not be working as intended or as needed by your phone. The normal situation is that the Palm supplied cable is a normal usb cable with no special pin configuration and the palm supplied adaptor is setup to short two pins (as indicated in the link above) to tell the phone to get into high current charging mode and draw more current. This is necessary because the original standard for current on the USB port didn't supply this much power and drawing too much could damage a port/charger that was not setup for it.

    An alternate way to force this behavior with an older ac adaptor is to build a cable that has the required pins shorted. This allows the device (phone in your case) to see this as a high current capable charger and draw accordingly.

    With your long cable and ac adaptor either your adaptor is not properly shorted or the cable has some fault that prevents the shorted pins from being detected by the phone. Either way the phone can't get into the high current draw and so it charges slowly.

    With your short cable and ac adaptor either your cable is shorted and this fixes the problem with the adaptor - or the cable is not broken and allows the phone to see the shorted pins in the charger correctly.

    At least that's what I think.

    If you really want to test this. Make sure you have a spare palm cable and ac adaptor and another short usb cable. Ideally you'd want to test all the pins with a multimeter but that's hard with these tiny connectors.

    Try Short cable 1 with AC adaptor 1, then Short cable 2 with AC adaptor 2, etc.

    Besides ad-hoc testing and looking at Govnah you could discharge the phone battery down to say 20% or so and then run Battery Monitor in graphing mode for say 10 mins with data collection set to 15 seconds while charging. Look at the graph and the average current data on the chart, then switch cables/adaptors and try again. This averaged data will give you more accurate info than just looking once or twice while charging and giving us the numbers. If you want to be very accurate - discharge the battery to a set point and stop the charging at the same point and then discharge back before trying the next condition. Ideally the phone should not be in use while charging to avoid using power differently in each test and changing the results - perhaps airplane mode?
  14. #14  
    Oh and my results were around 400ma when I first plugged my phone in (82% battery reported by Dr. Battery) and when it reached 97% it dropped to around 130ma or less.

    All with the Palm supplied standard cable and adaptor.

    Other tests done in my car show that some of my 12v usb chargers supply far less current than is needed for full charging speed - no matter what discharge state my battery is in some can not do more than around 200ma.
  15. #15  
    I agree, it shouldn't make a difference but I have noticed, only with usb, that when I plug in my WD external HD if I use a micro usb longer than 10inches it will not work, if I change the cord to the shorter one, it works like a charm. I have done little research into the matter but have found that even WD states that if the cord is to long it will not work. Weird I know but there is some factor we are missing...
  16. #16  
    Quote Originally Posted by BradleyCulbertson View Post
    I agree, it shouldn't make a difference but I have noticed, only with usb, that when I plug in my WD external HD if I use a micro usb longer than 10inches it will not work, if I change the cord to the shorter one, it works like a charm. I have done little research into the matter but have found that even WD states that if the cord is to long it will not work. Weird I know but there is some factor we are missing...
    In that case you may be dealing with something else like noise but I cannot say for sure. Ideally you might follow up with Western Digital and tell them that you want a technical explanation for why and maybe they will help you.
  17. #17  
    Time for me to get confused myself.

    I just had my phone replaced under warranty and now it no longer charges quickly. I don't have any short cables to test with - but my normal cable and palm external ac adapter have stopped charging my phone as quickly as before. When I look in Govnah the peak current is typically around 220ma or less while charging from the Palm branded ac adapter. I have 4 of these and 4 cables and all of them are acting the same. On the same phone charging from a USB port is between 220-300ma.

    Previous results had been closer to 450-500ma while charging from the AC adapter. I have multiple batteries so my next step is to try another one and see if that changes anything but I am pretty sure I already did that.

    I'm confused. Since this phone is "like new" refurb I wonder if there is a problem like the one I theorized earlier with the OP about the shorted pins not being read by the Pre's USB port reliably. (This is a Pre Plus on Verizon BTW - running 1.4.5 with ZERO patches.)
  18. #18  
    Quote Originally Posted by BradleyCulbertson View Post
    I agree, it shouldn't make a difference but I have noticed, only with usb, that when I plug in my WD external HD if I use a micro usb longer than 10inches it will not work, if I change the cord to the shorter one, it works like a charm. I have done little research into the matter but have found that even WD states that if the cord is to long it will not work. Weird I know but there is some factor we are missing...
    I think this is a whole different situation. In your case, the cable is being used for high speed data transfer, and at these higher frequencies the increase in impedance of a longer cable is much greater.

    Otherwise, I think Unclevanya nailed it re: shorted pins telling the device to take more current.

    Regards,
    Tom
  19. #19  
    Quote Originally Posted by akabadnews View Post
    Which answers the question I just asked myself last night.

    "Why does my phone charge faster plugged into the wall instead of the computer?"

    Thanks, guys. Lol
    the answer to that question is because your computer USB port puts out a maximum of 500mA and the wall adapter puts out 1000mA.
  20. #20  
    How much loss of power would there be on a 15ft usb to 5pin micro b charging cord thats 28/24awg and has a charger that is 12watt 2.4 amps 5.2volts
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