I have the fandyfire stl v6 so how does it compare.....
Yours is definitely output regulated, X9 i don't think so. If you want to operate 20mm shorter than X9 ie at 180mm length, you can use 2 x 18500.
Normal Ultrafire 1800mah ones would do (so you'd prob get 1000mAH conservatively, so it is like a 2000mAH 18650...not too bad). The IMR 18500 from bestinone.net is needed only for the 3 x XM-L lights like Trustfire/Fandyfire/SkyRay. Mitro already tested the IMRs and they are very close to rated cap, so you would not get any surprises there. ie 18500 1800mAH becomes 600mAH when you check with a hobby charger. LOL! But the IMRs are a wee bit more expensive.
Actually not really, http://www.manafont.com/product_info.php/protected-trustfire-18500-37v-1800mah-rechargeable-batteries-gray-2pcsset-p-5569
IMRs are 8.99/pr shipped. I think if you buy another $6 they can give you free registered shipping (MF does not, you add $2)
@2100....ok thanks.. well I wont bid on it then x9.Im also looking for one of those 6x cree Q5,Q4
what light do you suggest output regulated .....thanks
Your fandyfire is already a thrower, so i don't think you need one of those 5 * R2 or Q5 etc. Get a 3 x XM-L light which would also be able to share the same 2 x 18500 batts for shorty operation, but there are a few teething problems to sort out first for the Sky Ray. I have a Trustfire 3 x XM-L coming, lets see how it goes....
I have the Sky Ray, also the cnqualitygoods 150mm 3 x 18650 version is coming together with the Trustfire 3-cell model, also the TK70. I like 3 x XM-Ls! (only they have enough kick to arouse my senses). 6 x XM-L in Mag sizes would be way too floody for me, coz floods are only useful for me in smaller sizes.
I don't think 6*xml will be necessarily more floody, since their reflectors will occupy more of the head surface area. There is however a practical limit to how much power can be safely channeled in a cheaply made led flashlight and I think 20-30w is about it.