use a CC power supply to charge lithium cell?

[ice595]

From what I've heard, using a voltage source to charge lithium cells may result in a lot of smoke and flames 

But how about using a bench supply with CC mode to charge lithium cells?
Set the current limit to safe level (i.e 100mA) then set the open circuit voltage to 4.2v
In theory, when the lithium cell voltage reaches 4.2v, it will match the power supply's open circuit voltage and stops charging.
but how well does that work? has anyone attempted this before?

[eKretz]

Yup, do it all the time. Works great!

[rolycat]

I've done this as well, but charging does not stop when the voltage reaches 4.2 volts, and if you disconnect the supply at this point the cell will only be partly charged.

To get a full charge, leave the cell charging at 4.2V until the current reaches about 10% of the initial charge rate.  It's dangerous to leave lithium cells 'trickle charging', so you need to calculate the time at which this will occur and set an alarm so you don't leave it too long.

Unless it's an infrequent operation, you are much better off with a proper charger.

[eKretz]

Right, I typically charge 4 cells at a time in parallel and cut off charging when the amperage drops to 100-200mA.

[ice595]

is there a simple circuit to cut off charging then the current reaches a set amount?
my guess would be using a op-amp comparator circuit to do this.

[Len]

is there a simple circuit to cut off charging then the current reaches a set amount?
my guess would be using a op-amp comparator circuit to do this.

How about one of the simple Li-ion charge controllers? This one is cheap and looks easy to use (haven't tried it myself):
http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en024903

[Witention]

Check the cell data sheet to see if any voltage or current levels could damage or degrade the cell performance. Use the power supply's over voltage or over current protection features to ensure the power supply output shuts off if any unwanted voltage or current levels are reached.

[AndreaEl]

If it can help there are http://batteryuniversity.com/learn/ with a lot of information about battery.

in particular: Charging Lithium-ion: http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries