I posted the same topic in HKdiver, wish TXM of DOYOUHIKE show better performance than HK!
I used 8pcs SANYO AA 2700mah with adater to instead of C cells.
Then I did durance test for AA 2700 in air, C8 eLED burned more than 4 hours in high lumen.
Who knows how long AA 2700 (X 8）will burn with high lumen in water ?
It will totally depense on what kind of C Cells you are going to use!. If you use the Duracell alkaline C cell is 7800mah. 3X of the 2700mah. If you going to use the very cheap C cells you better know its power ???AH or ???mah. 1ah =1000mah.