5V - 12V step-up and simple 5V "smart" battery charger circuit

Discussion in 'The Projects Forum' started by jamikKim, Aug 20, 2010.

  1. jamikKim

    Thread Starter New Member

    Mar 7, 2010
    Hello all,

    I have a few cheap circuits I would like to make:

    The first is a 5V to 12V step-up converter; I found one here... This one should be easy enough, and I only need about 2W max. power from it. The power input is 5V 890mA from a phone wall ps.

    Using the same "charger", I would like to make a cheap, simple circuit that can detect when a 3.7V Li-ion battery is charged and hence stop charging at that point. These seem very interesting. Which one would you recommend? :)
  2. retched

    AAC Fanatic!

    Dec 5, 2009
    The LTC4054 is a great little charger.

    It is true to the post. SIMPLE. It has a maximum charge current of ~750ma

    So 1-hour or (fast-charging) certain cells will not happen. But it is better that you not concern yourself with such fire-worthy circuits yet.

    I would build the first one in the post. Easy. Gets you experience points and soldering 'iron time'.