Canon’s New CP-E4N Flash Battery Pack Explained
Always a useful source of technical information, Canon USA have published a post that outlines the details of the new CP-E4N battery pack that was launched alongside the new 600EX II-RT flash a couple of days ago. This battery pack allows a much faster recycling time with the new flash, but is also backwards compatible with the older 500-series and 600-series flashes.
Externally there are no differences to the older, now discontinued CP-E4 pack, but several internal changes have been made to improve recycle times and control heat build-up. Canon specifically mentions flame-retardant materials used for the housing, as well as stronger cable connections on both ends and quieter operation – a definite bonus for wedding photographers.
Whilst this pack will work with some older flashes, it seems that it will work better with the 600EX II-RT because it is using a new communication protocol to send power and heat information to the flash.
Data from Canon
Recycle Time, at full 1/1 manual power:
Speedlite 600EX II RT alone — approx. 5.5 seconds (alkaline AAs); 3.5 sec. (Ni-MH)
600EX II-RT plus CP-E4N — approx. 1.8 seconds (alkaline AAs); 1.2 sec. (Ni-MH)
Number of flashes, at full 1/1 manual power:
Speedlite 600EX II-RT alone — approx. 100 (alkaline AAs); approx. 112 (Ni-MH)
600EX II-RT plus CP-E4N — approx. 300 (alkaline AAs); approx. 336 (Ni-MH)
Number of continuous, full-power shots before Level 1 protection engages:
600EX II-RT with previous CP-E4 pack — 45 to 70 flashes
600EX II-RT with updated CP-E4N pack — 60 to 100 flashes