Just gonna throw out an idea Here. Im thinking a Comparator circuit that checks the battery's voltage. Cells only need to be balanced if they are Over 4.2V, Correct? Under charging really isnt too much of a issue. So, If i have the comparator trigger a small load (say 100 mA) if the batteries voltage is over 4.3V and then turn off once the voltage reaches 4.2V. Im thinking this would achieve balance, and not risk damaging the cells. The only thing is, would I use a Comparator with Hysteresis?
That is what the circuit in post 17 does. The Tl431 is a voltage reference that can be set to turn on the shunt transistor to "steal" the current from the battery that is already at 4.2 volts. These work okay for low currents like you were talking about (100 - 200 ma. or so).