Converting LI powered cell phone to alkali

Discussion in 'The Projects Forum' started by PartyLine4, Feb 11, 2013.

  1. PartyLine4

    Thread Starter New Member

    Jan 12, 2013
    27
    0
    I have a cheapy trac-fone who's charger just broke. So instead of buying a new charger for the price of a new phone, I have soldered wires to the + and - leads on the phone.

    The phone uses a 3.7v 800mah litium ion battery. I suspect the battery actually charges to 4.?? volts.

    I don't know the current draw of the phone so I can't be 100% sure on what to put in series with 3 AA cells to limit the voltage/current.

    Any help on how to proceed is needed. I have minutes on the phone and want to keep them!
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,035
    3,241
    Three NiMH batteries would have a series voltage of 3.6V which should power your phone just fine. You don't need to limit the current.

    What's the voltage and current output of the charger. It shouldn't cost that much to get a new generic one.
     
  3. tinamishra

    New Member

    Dec 1, 2012
    39
    1
    I am agreed with idea of Three NiMH batteries.
     
  4. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    Yep, or NI-CD would also work fine.
     
  5. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
    If you have some old chargers with the same output voltage. It would probably be more easy to just swap plugs
     
  6. MMH

    Member

    Feb 8, 2013
    143
    4
    Or...

    You might be making your very own charger. Just change the plug of the charger and resistors to get a regulated 4.2v. By the way, if you charge the Li-lion Battery while it is inside yor device, it means that there is a built in charger.In that case, 5 volt and 500 mA should be given to the device.

    Hope it helps.
     
Loading...