Building a battery charger for AAA Ni-MH batteries.

Discussion in 'The Projects Forum' started by douce52, Jan 31, 2008.

  1. douce52

    Thread Starter New Member

    Jan 31, 2008
    1
    0
    Hello.

    I am new to the electronics hobby and I would like my firt project to be a battery charger for my AAA NI-Mh batteries which are rated at 1.2 V.

    I have found many examples of circuits to build. However, they are all for Alkaline batteries. I know I have to limit the voltage and amps coming form the wall to the batteries and I have to be mindful of over heating.

    My question is do I have do anything different because my batteries are 1.2V and not 1.5V and because they are Ni-MH and not Alkaline?

    Thank you
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    293
  3. Audioguru

    Expert

    Dec 20, 2007
    10,484
    1,157
    A Ni-MH cell is 1.4V to 1.5V when it is fully charged.
     
  4. Gadget

    Distinguished Member

    Jan 10, 2006
    613
    0
    Dont ever charge my NiMH cells.. !!!.
     
  5. Audioguru

    Expert

    Dec 20, 2007
    10,484
    1,157
    My RC airplane is powered by an 8.4V Ni-MH battery that has seven AAA cells. Its capacity is 900mAh.
    I charge it at 180mA for 6 hours when its voltage reaches 10.4V and it is beginning to get warm.
     
  6. Søren

    Senior Member

    Sep 2, 2006
    472
    30
    Hi,

    Ehh?
     
  7. hgmjr

    Retired Moderator

    Jan 28, 2005
    9,030
    218
    Here is one individual's solution for the design of a Ni-MH battery charger. I'm not sure why anyone would think that Ni-MH type batteries are not rechargeable.

    hgmjr
     
Loading...