Battery charging @ low current

Discussion in 'The Projects Forum' started by rakeshm55, Mar 5, 2011.

  1. rakeshm55

    Thread Starter Member

    Oct 19, 2010
    68
    0
    Hi,
    I want to recharge li-ion batteries with a low current 100mA(in CC-CV mode) . Is it really advisable?? will it affect the battery life??
    At this charge rate i presume I no need to have temperature protection right??

    Battery capacity is of 2200mAh. So as an estimate it takes about 22hours to recharge!!
     
  2. wayneh

    Expert

    Sep 9, 2010
    12,120
    3,046
    Not sure what your charging strategy really is. Can you post a schematic of your circuit? Constant 100mA is too slow (although OK) at the beginning and too much at the end, and will cause overcharging if left connected.
     
  3. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,788
    945
    http://www.powerstream.com/li.htm

    Lithium-ion batteries can become dangerous if over charged(explode). DO NOT TRICKLE CHARGE THEM

    Fast charge to 4.2 V, then hold 4.2 volt until charging current drops to 10% of the initial value. (about 100-200 mA) THEN STOP They are then as fully charged as it is SAFE to charge them. Anymore current input will likely damage them and create a safety hazard.

    They are not like other batteries with which we are all familiar.
     
  4. rakeshm55

    Thread Starter Member

    Oct 19, 2010
    68
    0
    Hi,
    I am using separate chip for charging....It charges in CC-CV mode.....
    Constant current is 100mA. Once the voltage reaches near 4.2V the charger will switch over to Constant voltage mode (4.2V with 6% accuracy) and charge untill the taper current reaches 10mA and then enters to an auto shutdown mode where battery discharge would be 2uA.

    the scenario is as follows

    Battery charger IC ----> Battery (3.7V lithium ion) -----> OR controller...

    My query was this 100mA of charging will it have a negative impact on battery life and do i need a temperature protection. 100mA is too low a current so the battery wont over heat!! am i correct???
     
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