Mobile charger to charge LiIon batteries, Usng Voltage Divider to drop voltage

hii have a lot of mobile phone charges that say "output 5v .7A" i want to use it to charge a liion battery..both prismatic and cylindrical 18650.i have few question..

What does the figures in output mean ? does it means its a CC/CV output ?

Can i use a Voltage Divider Circuit to Drop the extra voltages and get 4.2volts and then connect those 4.2 volts to the output of protected 18650 cell or unprotected liion cell ( saftey against over charge is gauranteed by firstly the fact that when the battery voltage equals the charger output voltage no more current flows and secondly i will be constantly observing it..) while reading about Voltage divider network in the book "Electic Circuits" by Nilsson it mentioned that the as long as the Load Resistance is very very greater then R2 ( wheare as r1 and r2 are the two series resistors and r2 is the resistor accros which i will be geting output ) ..the output voltage remains fairly constant.. ? so in my case the load is cell what should be its resistance ?


Thanks

 

thanks man it was helpfull..

regarding whether the output of charger is CC/CV i m still a bit doubt full i tied few resistors in series.. and the current was lowering then the mentioned output so should it be safe to say its not CC ?

now i need to chose suitable resistors and go and test it..
here is some of my calculations ..i scanned the page please see it..

what should be the ideal resistor value/rating ... considering that i will be charging the battery at say 600 mA .. so Ic in my circuit will be 600mA and hopefully at least 600mA will also be flowing through R1.. what should be the current through R2 ?
and i am also attaching the pge from nilsson book about vdr