JakeSoft: The problem with using an AA battery holder for the cells is that the battery holder itself also takes up space. It might still fit, though. It's worth looking into.
i like the 1500mah. bonus. twice as mush as TCSS Batt holder- right. but with one... maybe 3mm of girth added, and the plus side is the back is capable of gluing crap too. now you can use removable batts. just saying. as a 3.7v option for the Canobi Express it maybe the best option. other than a Lipo.
i bought this. it is an 14650 and took the outer wrapper off so i could shoot the cable straight out the top. the 90 degree protruding cable was chafing on the hilt threads. it is 1.5cm longer than 14500. but 2 for $15... spoke my language. but i can't find a twin 18650 over 850mah. makes no sense. the single are 2200+