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how does a cell phone detect a "genuine" battery

Discussion in 'Electronic Repair' started by Dan Lenski, Dec 24, 2006.

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  1. Dan Lenski

    Dan Lenski Guest

    Here's the next item on my "to-fix" list while home for the holidays...

    I have before me a Motorola E815 cell phone which will not charge. The
    battery is fine, just the phone won't make a connection to the charger.
    I found an old LG cell phone with battery, which works fine.

    Since every single cell phone I've ever seen uses a 3.7V Li-Ion
    battery, and since I don't have a programmable voltage supply with me,
    I figured I could use the LG cell phone to charge the Motorola battery.
    The LG cell phone and its battery have 4 contacts:

    | | | |
    NEG NEG MYSTERY POS

    and the Motorola cell phone has 4 contacts as well:

    | | | |
    NEG NEG MYSTERY POS

    I figured I could just connect the +/- terminals of the LG phone to
    those of the Motorola battery, and the Positive terminals together, and
    then the LG phone would see it has a drained battery and merrily charge
    it up.

    Not so! When I did this, the LG phone said "Use genuine battery!" and
    refused to charge it. WTF?!?! It seems like there's some kind of
    "counterfeit detection" circuit in the battery to make it harder to
    make cheap knockoff batteries. I assume this comes from the "mystery"
    contact. Is there information somewhere on how to fool this idiotic
    counterfeit detection circuit?

    Thanks,

    Dan
     
  2. Ken Weitzel

    Ken Weitzel Guest

    Hi Dan...

    It's for your own protection, I'd recommend not trying to defeat it.

    Take care, and happy holidays.

    Ken
     
  3. Dan Lenski

    Dan Lenski Guest

    Thanks Ken, but I don't need any protection :) I have a long history
    of doing things with my electronics that they were never meant to do,
    and it's worked well for me.

    It's ridiculous that a cell phone demands a particular brand of
    battery, considering that essentially all cell phones use 3.7V LiIon
    batteries which differ only in capacity and shape. Plus I don't really
    care about protecting the phone, since I only want to use it as a
    charger for this battery.

    I'm wondering if the "genuine battery detection" is something trivial
    like "connect a 100k resistor between the mystery contact and ground"
    or something complicated involving a microcontroller in the battery
    that uses some serial protocol to communicate a message back and forth.

    Dan
     
  4. Jamie

    Jamie Guest

    put a scope on the mystery leg, you'll most likely see a serial stream
    coming out of it.
    try blocking off that leg.
     
  5. Some inkjet cartridges are chipped to prevent refilling or cloning. Could be
    a similar nasty trick.
     
  6. Ken Weitzel

    Ken Weitzel Guest

    Hi Dan...

    Not so sure that we don't need a bit of protection... thinking of the
    exploding and burning batteries in laptops recently... third party
    and counterfeit batteries are out there, and it won't be long before
    making them with small capacity and mis-marking them, so...

    Anyway, I have no idea, other than guesses. Jamie suggest that it might
    be a serial connection to the phone. That sounds good, if LG doesn't
    want you to buy any of their competitors products, but might be
    expensive to implement.

    I'm wondering if it might not be as simple as a temperature detector...
    something as easy as a pair of diodes back to back. Or maybe even a
    thermal fuse.

    Another thought is if someone here has a battery that's dead beyond
    any use at all, perhaps they'd open it up and see what's in there?

    Wish I knew more. :)

    Take care.

    Ken
     

  7. Just because they are the same voltage doesn't mean that they use the
    same cells inside. Maxim and others make ICs for this application.


    --
    Service to my country? Been there, Done that, and I've got my DD214 to
    prove it.
    Member of DAV #85.

    Michael A. Terrell
    Central Florida
     
  8. Meat Plow

    Meat Plow Guest

    I'd listen to Ken. Hate to see you have a phone in you pocket and have the
    LiON battery do a meltdown.
     
  9. Bob Urz

    Bob Urz Guest


    http://www.maxim-ic.com/1-Wire.cfm

    bob
     
  10. JANA

    JANA Guest

    Many of the manufactures are starting to make their products in a manner to
    have increased safety. Inside of many of the dedicated batteries, the
    manufactures are using chip technology to not allow them to be charged if
    they are not the original product. The manufactures are trying to protect
    themselves and the end users, regardless of the knowledge of the person
    trying to defeat its purpose.

    --

    JANA
    _____


    Here's the next item on my "to-fix" list while home for the holidays...

    I have before me a Motorola E815 cell phone which will not charge. The
    battery is fine, just the phone won't make a connection to the charger.
    I found an old LG cell phone with battery, which works fine.

    Since every single cell phone I've ever seen uses a 3.7V Li-Ion
    battery, and since I don't have a programmable voltage supply with me,
    I figured I could use the LG cell phone to charge the Motorola battery.
    The LG cell phone and its battery have 4 contacts:

    | | | |
    NEG NEG MYSTERY POS

    and the Motorola cell phone has 4 contacts as well:

    | | | |
    NEG NEG MYSTERY POS

    I figured I could just connect the +/- terminals of the LG phone to
    those of the Motorola battery, and the Positive terminals together, and
    then the LG phone would see it has a drained battery and merrily charge
    it up.

    Not so! When I did this, the LG phone said "Use genuine battery!" and
    refused to charge it. WTF?!?! It seems like there's some kind of
    "counterfeit detection" circuit in the battery to make it harder to
    make cheap knockoff batteries. I assume this comes from the "mystery"
    contact. Is there information somewhere on how to fool this idiotic
    counterfeit detection circuit?

    Thanks,

    Dan
     
  11. AZ Nomad

    AZ Nomad Guest

    The only thing they're protecting is their profit margin.
     
  12. I was reading about this in the industry trade rags (Electronic
    Design, EETimes) this last summer.

    Unfortunately, it's not likely to be easy to defeat. The system I
    came across was described as having a custom IC (a microcontroller plus
    a serial port) built right into the battery. Said microcontroller is
    mask-programmed with a unique and encrypted ID at the time of
    manufacture, and it enters into a complex handshaking sequence with the
    phone's innards before the phone will accept it and power up.

    I'm not saying it can't be cracked -- Anything electronic can be.
    However, the kinds of resources and test gear you'd need to do it would
    exceed, by many orders of magnitude, the cost of a genuine battery
    gotten from, say, Greed-bay.

    I used to think the counterfeit detectors were a bad idea. However,
    given all the low-quality knock-off batteries that have exploded and
    burned in recent years, some causing nasty injuries, I'm not so sure.

    Happy tweaking.
     
  13. Like the ink for inkjet printers - it's more expensive than the finest
    champagne.
     
  14. No, they're protecting themselves against liability issues.
    Personally, I don't mind paying a bit extra to avoid a potential fire
    or problem.

    Note that the defective Sony batteries were caused by microscopic
    impurities in manufacturing.

    There's a good article on the safety of LiIon and LiPo batteries in
    the current issue of Nuts and Volts, but it's not online.

    Meltdown is sorta fun, but not inside my cell phone or laptop.





    http://video.google.com/videoplay?docid=-7999636960714830130
     
  15. AZ Nomad

    AZ Nomad Guest

    bullshit.

    If the battery explodes and the phone is operating within specs, it is
    the batteries fault. Not the carrying case. Not the owner. Not the
    clothing being worn by the cell phone owner. Not the power lines leading
    to the house where the phone was charged.

    <snip irrelevent videos>
     
  16. Franc Zabkar

    Franc Zabkar Guest

    Is it possible to swap the electronic innards? If so, is there any
    reason why it would not be safe to do so? Wouldn't the cell
    chemistries be identical?

    - Franc Zabkar
     
  17. [/QUOTE]
    Can you offer a better explanation of what went wrong with the Sony
    batteries? I'm only recycling what I've read on the internet which
    also notes that manufacturers are switching to metal oxide insulators
    that will not conduct heat or cause a fire. Perhaps you have inside
    information? URL's that offer explanations other than crud imbedded
    in the polyolefin insulators are acceptable.
    Correct. I have the honor of suing the manufacturer in China if my
    house burns down as a result of having the cell phone catch fire in
    the charger. Chances of collecting damages is about zero. Granted,
    the risk of fire is very low, but I'm not interested in proving the
    point.
    How about counterfeit battery incidents? Is that sufficiently
    relevent?
    <http://www.cpsc.gov/cpscpub/prerel/prhtml04/04559.html>
    <http://www.hc-sc.gc.ca/ahc-asc/media/advisories-avis/2006/2006_41_e.html>
    <http://www.kodak.com/eknec/PageQuerier.jhtml?pq-path=7075&pq-locale=en_US>
    <http://www.cbsnews.com/stories/2004/10/28/tech/main652128.shtml>
    <http://www.havocscope.com/Counterfeit/batteries.htm>
    <http://www.canon-europe.com/For_Home/Product_Finder/Cameras/Digital_Camera/counterfeit_batteries.asp>
    <http://www.nema.org/gov/anti-counterfeiting/upload/Counterfeit White Paper_ver8.htm>
    (Lots more. Just search Google for "counterfeit batteries")

    NEC also makes counterfeit battery detector chips:
    <http://necel.com/news/en/archive/0407/0601.html>
     
  18. Ken Weitzel

    Ken Weitzel Guest

    <snip>

    Respectfully suggest you put suing someone to reclaim your monetary
    losses if your house burns down on the back burner.

    Think instead about who and how you can sue for the losses of your kids
    and/or grandkids if they're sleeping in your house when it goes up. Or
    riding in your car when it "explodes" and indirectly causes an accident.
    Puts a whole new light on it, eh?

    Take care.

    Ken
     
  19. AZ Nomad

    AZ Nomad Guest

    Putting an anti-competitive chip in those batteries wouldn't have made
    any difference.
     
  20. One my pastimes is collecting product liability horror stories.
    There's a real possibility of winning such a judgment based on past
    precedents. However, that usually only works for the initial
    litigation as subsequent "me-too" litigation tends to be far less
    successful. There are exceptions (asbestos, Vioxx, etc).
    Agreed. However, methinks you misread what I scribbled. I didn't
    recommend litigation. I suggested that one buy an approved battery to
    avoid the problem in the first place. I also mentioned that
    litigation against a battery counterfeiter in China is essentially
    futile.

    However, I'm starting to wonder if genuine OEM batteries will really
    will help. The original exploding Nokia batteries were genuine Nokia
    and not counterfeits. Some batteries apparently have no short circuit
    protection.
    <http://www.theregister.co.uk/2003/11/10/nokia_batteries_not_safe_either/>
    <http://www.theregister.co.uk/2005/03/14/nokia_thailand_handset/>

    What bothers me is the number of my customers that don't even bother
    to check if their laptops have potentially defective Sony batteries.
    I've had to call them for the models and serial numbers.

    Assorted battery recall pages:
    <http://www.cpsc.gov/cpscpub/prerel/prhtml07/07011.html>
    <https://www.dellbatteryprogram.com>
    <http://bpr.hpordercenter.com/bpr/us-en/>
    <http://www.lenovo.com/batteryprogram/>
    <http://esupport.sony.com/battery/>
    <https://support.apple.com/ibook_powerbook/batteryexchange/>
    <http://www.computers.us.fujitsu.com/battery/>
    <http://www.gateway.com/battery/>
    I think taking care pills requires a prescription.
     
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