Consensus here seems to be, and many vendors will have a similar blurb...... if it's a 450mAh or more, then the regular 'fast charger' eGo charger (4.2V 420mA spec) should be good. Below 420mAh on the batt, you might want to try a 'slow charger' with lower mA in the specs.
That said, there are many who have used the eGo charger on the 350mAh batts, evidently without a problem. When I went looking for a mini - I went with the 450mAh for that reason above.