I was using a 901 battery extension with a hole drilled in the side. Now I just finished using a Dremel to drill a 1/32" hole through the base of the 901 battery threads (from one side to the other.) Now it works just like an 808 battery (draw) and still works the same with my 901 attys. Finally, a good use for that new 5-pack of 901 batts that have been sitting around since I got my 808...