LiPo Charging without Charger

Discussion in 'Power Electronics' started by jrevard, Jun 24, 2016.

  1. jrevard

    Thread Starter New Member

    Jan 6, 2014
    Is it possible to charge a lipo (e.g. 3.7V, 40mAh, without a charger (i.e. with straight DC power). If so I realize there would be current limitations. I built a DC power source with an LM317, could I build a circuit around it to charge this battery?
  2. Stuartambient

    New Member

    Jun 24, 2016
    I'm new here and new to electronics for the most part. What I wanted to point out is that specifically that battery you link to is a Lithium-Ion, not Polymer. Slight difference but the charging methods are about the same. You could build a circuit around that unit but you need something in the circuit that will be able to monitor the capacity of the battery as it is charging. Hopefully someone else can give you a more concrete answer.
  3. tcmtech

    Distinguished Member

    Nov 4, 2013
    If you keep your charging voltage within the upper rated limit of the battery, ~4.2 volts per cell, in question normal constant voltage source based charging is not a problem. Odds are you won't even need any real degree of current limiting either.
    I charge lithium based battery cells and packs like that all the time and have yet to ever have any issue with it.