Charging a Lithium ion with a solar panel

Discussion in 'The Projects Forum' started by ozirock, Feb 19, 2013.

  1. ozirock

    Thread Starter Active Member

    Jan 13, 2011
    Hi Guy's,

    I'm making a solar panel for experimenting and was wondering if someone could confirm that I would be able to charge a battery like the one on ebay here using a solar panel regulated to the current and voltage spec of the AC adapter that comes with the charger. It seems to me that any charging control is done in the battery itself rather than that AC adapter which is supplied so I don't see where there would be a problem unless the power dropping in low sunlight would cause problems?

    Thanks in advance!
  2. tindel

    Well-Known Member

    Sep 16, 2012
    It's hard to tell where the charge circuitry is. They do say to use the 'supplied charger'. Which is scary since there doesn't appear to be any feedback from the battery, but it's hard to tell. Maybe email them and try to find out where the charge circuitry is located.

    I certainly wouldn't try charging the battery without knowing where the charge circuitry is.
  3. ozirock

    Thread Starter Active Member

    Jan 13, 2011
    Yes I had actually missed the part about the "specialized accesory" to recharge, I need to read these things more carefully but I'm hoping that the person who wrote that was some form of sales rep and wouldn't know any better :p

    I'll shoot them an email anyway and see what they say, alternatively I could just buy it take apart the ac power adapter and take a look to see what I'm dealing with. I could use the battery for something else anyway if it didn't suit.

    Thanks for giving me someone to bounce the idea off.
  4. RamaD

    Senior Member

    Dec 4, 2009
    Li Ions are charged almost like lead acid. You could charge them at 0.5C. It is better to monitor the temperature.
    But a major difference is, you just cant overcharge them. The charging potential 4.2V per cell, and this just cant be more. It is preferable to charge to a little less, say 4.0V or so, which would hold almost 90% charge. My phone battery says 91% charge and the voltage is 4.07.

    The following link has very good info.