Canon 550EX - Manual (Page 11)

Installing Batteries
Battery Cautions
• Use four new batteries of the same type. When replacing batteries, replace all four
batteries at one time
• Although non-alkaline batteries (R6) may also be used, the number of flashes will be
less
• The contacts of Nicad batteries are not standardized. If you want to use Nicad
batteries, make sure the battery contacts touch the battery compartment's contacts
securely,
• Remove the batteries when the Speedlite will not be used tor an extended period.
• In low temperatures, take two sets of fully-charged Nicad batteries and keep one set
warm in a pocket, etc., and use the batteries alternately,
• To prevent faulty connections, make sure the battery contacts are clean. If necessary,
use a clean cloth to wipe the battery contacts.
• Size-AA lithium FR6 batteries can also be used
Recharging Time and Available Flashes
Battery Type
Recharging Time
Available Flashes
Quick Flash Normal Flash
Size-AA alkaline
LR6 batteries
Approx. 0 1-4 sec Approx. 0,1 - 8 sec Approx. 100 to 700
Size-AA Nicad
KR15/51 batteries
Approx. 0.1 - 2.5 sec. Approx 0 1-5 sec. Approx. 40 to 300
The minimum recharging time applies to the E-TTL or TTL mode while the maximum recharging
time applies to the manual or full-output (1/1) mode.
The minimum available flashes applies to the E-TTL or TTL mode while the maximum available
flashes applies to the manual or full-output (1/1) mode.
The above data are based on Canon’s standard tests with new batteries
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