The Canon NB-E3 rechargeable NiMH battery works for Canon EOS-1D, 1DS & 1D Mark II digital cameras. It features no memory effect that lets you recharge partially drained batteries without reducing performance.
This powerful battery pack is dedicated to the Power Drive Booster PB-E2. The rated voltage is 12V. It can be recharged over 500 times. When fully charged, it has enough power for 70 rolls of 36-exposure film at 20 Degrees.