BT-C3100 max power available for driving replacement fan (HKJ?)

I am modding several BT-C3100 chargers. Screeching little fans got to me.

HKJ worked with another poster to determine what power the charger could supply for the controlled fan. But the post did not have the max power info. Just what was used.

I need to know the max safe current X voltage the driver on the charger can provide. I am using a fan underneath the modded fan case. It is a big fan. Pretty much the width of the charger case. I want it to be able to use the controlled output built into the charger.

If I can find that out, I can use a resistor to adjust the power used by the fan. There was an earlier number from the manufacturer, but it was not stated as a max.

If anyone knows what the actual numbers are, I would much appreciate the info.