Canon PowerShot A 640 User Manual page 155

• The CB-5AH/CB-5AHE battery charger can only be used
to charge Canon AA-size NiMH Battery NB-3AH and NB-
2AH. Please do not attempt to charge any other type of
battery. '
• Do not mix batteries with different purchase dates or
different charge states. When recharging batteries, always
recharge all 4 of them at the same time.
• Do not attempt to recharge fully charged batteries, as
doing so may reduce or impair battery performance. Also,
do not charge batteries for more than 24 consecutive
hours.
• Do not recharge batteries in enclosed areas that tend to
retain heat.
• Do not recharge the batteries until the LCD monitor
displays the "Change the batteries" message. Repeatedly
recharging batteries before they become fully depleted
may cause batteries to lose capacity.
• Wipe the battery terminals well with a dry cloth in the
following situations, as the terminals may be soiled with oil
from one's skin or other dirt:
- If the battery usage time has considerably diminished
- If the number of recordable images has considerably
diminished
- When charging the batteries (insert and remove the
batteries two or three times before charging)
- When charging completes in a space of a few minutes
(the battery charger indicator remains lit)
• You may not be able to fully charge the batteries due to
their specifications right after purchase or after long
periods of nonuse. If this happens, after fully charging
them, use the batteries until their charge is fully depleted.
After doing this several times, battery performance will be
restored.
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