A basic solar charger circuit?

Discussion in 'The Projects Forum' started by leche, Apr 1, 2011.

  1. leche

    Thread Starter New Member

    Apr 1, 2011
    14
    0
    Hi everyone.This is my first post.My english not so dvanced, so sorry for my slippery language :).I am a beginner on circuits.I wanted to create a solar charger circuit to charge my nokia 5800 and some AAA (or AA) batteries.It was easy to charge the cellphone just by an ic7805 what is connected to solar cell (6v 150MaH).But While charging the AAA batteries i need to see charging level or i want to see when charging is completed.So i found a max1501 smart charger circuit but i was too hard to crate it for me bacause it had a microchip so i had to program it etc.So now i just need a solar charger which can charge both my nokia 5800 and 4 AAA batteries.Do you have any circuits what adapts my needs?Thanks for everthing already now.:)
     
  2. wayneh

    Expert

    Sep 9, 2010
    12,127
    3,049
    What kind of AAA batteries, NiMH? Your 5v constant voltage supply won't take them to full charge, but will do an OK job of charging them up to 1.25v each cell. That's a reasonable percent of full charge.

    Adding a diode between the ground pin of the 7805 and ground will, I think, add ~0.7 volts to your output voltage. That would take you to 1.425v or so, and this is full charge. The higher voltage might be fine for your phone, so you'd have no worry using it for both duties, but I'm not sure I would risk it.
     
  3. leche

    Thread Starter New Member

    Apr 1, 2011
    14
    0
    Yes i want to charge NiMH Batteries.Can you show me a circuit to provide?Also it is so important to watch charging current level of the batteries to protect them from overcharging.
     
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