I did an experimental test to see how the charger handled charging a single cell at 2 Amp's. I had to power the board from a power supply through the unmarked pad next to the USB connector. This bypasses the polyfuse and allowed me to achieve the full 2A charge current. The end result was a fully charged 2200mAh battery in just barely over 80min (the scale at the bottom is in seconds). The 100uH inductor (some of the images show a 270uH inductor, but the final is 100uH) got up to 55°C and the battery ended at 39.8°C. I would say this is pretty much the most current I would want to run this charger at. In general I would stick to a maximum of 1Amp (or close to that).