USB cell phone charger dead?

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While I was on vacation, I had my USB charger hooked up from my work laptop to my cell phone to charge my cell phone battery. Well, my wife shut the computer off while I was sleeping. I forgot to remove the phone from the USB cord. Now, my cell phone won't charge using the special USB cord I have for it. I've tried different USB ports and computers. Usually, when it is hooked up, the phone will beep and a charging icon shows up on the phone. Now, nothing. It's a Samsung SGH A-517. Anyway I can verify if the USB cord is bad or the cell phone battery shorted out?
 

Bill in Utah

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You have the original AC or car adapter? If you do try it, if it works then the USB has a problem. Also take the battery out of the phone and wait a min or so, then try it again just to see if the phone just got locked up. (Happens all the time with my work Nex-Tel) Bill
 

JHZR2

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Does the phone accept charge another way? Might the computer and phone having been off have defeated some protective circuitry, allowing the battery to discharge below a threshold level? Battery management systems will not allow for a normal charge after an overdischarge due to safety issues. If nothing charges it, I'd try warming the battery, but NEVER higher than 60c, to lower impedance and boost voltage a bit. This may allow the bms to allow the battery to accept a charge.
 

Cutehumor

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 Originally Posted By: Bill in Utah
You have the original AC or car adapter? If you do try it, if it works then the USB has a problem. Also take the battery out of the phone and wait a min or so, then try it again just to see if the phone just got locked up. (Happens all the time with my work Nex-Tel) Bill
sad to say, I only have the usb cord charger. I'm trying the battery now
 

Cutehumor

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 Originally Posted By: JHZR2
Does the phone accept charge another way? Might the computer and phone having been off have defeated some protective circuitry, allowing the battery to discharge below a threshold level? Battery management systems will not allow for a normal charge after an overdischarge due to safety issues. If nothing charges it, I'd try warming the battery, but NEVER higher than 60c, to lower impedance and boost voltage a bit. This may allow the bms to allow the battery to accept a charge.
It charges through the same port with a USB cord or with an AC adapter. I don't have an AC adapter though. It was strange. the phone had maybe 2/3 battery when I was charging it. I left it charging through the USB on the laptop. My wife shut the laptop off while the phone was charging, the next morning the cell phone battery was dead. what should I try to use to warm the battery? There's a warning on the battery about not using fire or heating it. If it's not working, might as well see what happens, eh?
 
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Bill in Utah

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Clean the contacts of the battery and inside the phone. I doubt anything is wrong with the battery or cable. Its most likely that the phone is locked up. Take the battery out, clean up everything, If you have a simm card, take it out and clean it up, wait 10 mins and put everything back together. If it still does not work, try another cord (go to a radio shack and they can set you up to see if its the phone or cord) Bill
 

JHZR2

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 Originally Posted By: Cutehumor
 Originally Posted By: JHZR2
Does the phone accept charge another way? Might the computer and phone having been off have defeated some protective circuitry, allowing the battery to discharge below a threshold level? Battery management systems will not allow for a normal charge after an overdischarge due to safety issues. If nothing charges it, I'd try warming the battery, but NEVER higher than 60c, to lower impedance and boost voltage a bit. This may allow the bms to allow the battery to accept a charge.
It charges through the same port with a USB cord or with an AC adapter. I don't have an AC adapter though. It was strange. the phone had maybe 2/3 battery when I was charging it. I left it charging through the USB on the laptop. My wife shut the laptop off while the phone was charging, the next morning the cell phone battery was dead. what should I try to use to warm the battery? There's a warning on the battery about not using fire or heating it. If it's not working, might as well see what happens, eh?
The electrolyte in a lithium-ion battery irreversibly degrades at temperatures over 65C. 60C is the hottest you want it to be. That said, being 40C or so, just warmed up would help... you definitely do not want to overheat it - thermal runaway and fire can occur. I'd just try to warm it up near an incandescent light bulb or similar low-level source of warmth. The electrical safety devices will prevent a battery that is overdischarged from accepting a charge. I believe that there is no diode or discharge protection in the wire, and so current flowed from the battery back. I think that it allowed somehow an overdischarge, which can commonly happen, and now the safety devices will not allow a recharge. This is common, i.e. a "locked" battery. If the phone is "locked", great. Perhaps the electrical safety devices are in the battery - and a dirty contact would prevent a proper voltage measurement, if that is how it is set up (I'm not completely sure how the safety devices are set up in a phone, to be honest, just larger stuff - but safeties DO exist in all Li batteries) Clean things up, Allow things to reset... But if you can put a multimeter on the contacts of the battery and get us a voltage, it would be real helpful to see where things are at...
 

Cutehumor

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I just used my analog voltmeter. I'm getting almost 4 volts out of the cell phone battery. my battery is rated at 3.7 V. So the battery seems fine. the contacts look a little scratched though. I'm going to go clean them. If cleaning the contacts don't work, I guess the usb cable died or the connector inside the phone shorted out?
 
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Cutehumor

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I finally got my phone to charge. but I have to push the USB cord and the charger port as hard as I can to get the phone to beep for charging. Looks like I need another charger cord.
 
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