I was more than paranoid using the cell phone charger, first off, I tested the voltage output and realized that the draw from charging the batteries would affect the output voltage of the charger over time. I found that it would take about 5 minutes to add .01v charge, but as the cell voltage increased, this time period decreased. When the cells hit 3.70v, one minute later it was at 3.73v... It'd be nice to have an audible alarm when the cells hit the "sweet spot" (I'm aiming for 3.8v, but the manual that came with them says 4.2 is "fully charged")

I would not let it sit connected and plugged in without supervision - that would be a recipe for disaster as my initial tests showed the charger putting out about 6.34v without a load. It'd cook the cells for sure... No overnight charging for me with that one.

I am curious tho, the 3.2v charger you use, will that charge the cells up to 3.8v or so? I was not sure about those single cell chargers, hence the cell phone 3.7v route.