A charger that operates at 3v isn't going to work on the 18650's I don't believe. My Trustfire TR001 has an output voltage of 4.2v and that's what you need. It also puts out 500mah into 2 channels. The charger you've got just isn't designed for doing 18650's. I may be wrong though so why don't you ask in the general forum so you'll get several opinions.
I charged 1850 mAh with that charger before, but 2600 mAh is a big difference, so I'll guess I'll throw in the charger as well