The shooting capacity of the Power Drive Booster E1 with the respective power sources is listed below: (with 24-exposure roll) Temperature AA-size alkaline Ni-Cd Pack E1 Normal (20oC) 100 (65) rolls 65 (45) rolls Low (-20oC) 6 (4) rolls 45 (30) rolls Shooting capacities in parentheses are for 36-exposure film. When used with AA-size Lithium, my own personal experience was: Approximately 300 rolls under normal temperature, half the capacity if the electronic focusing types of USM telephoto lenses like the EF 300mm f/2.8L USM or the EF 400mm f/2.8L USM are used all the time compared to the normal, non-electronic Full-time manual focusing-type of EF USM lenses on 36-exposure film. << Back to Main . 1 . 2 . 3 . 4 . 5 .