Canon EOS R3 Advanced User's Manual page 48

Upon purchase, the battery is not fully charged.
Charge the battery before use.
Charge the battery on the day before or on the day it is to be used.
Charged batteries gradually lose their charge, even when they are not used.
After charging the battery, remove it and disconnect the charger from the power
outlet.
When not using the battery or charger, reattach the included protective covers.
Use the battery in an ambient temperature range of 0–45°C/32–113°F.
For optimal battery performance, use batteries where the ambient temperature is 10–
30°C/50–86°F. Lower temperatures may temporarily lower battery performance and
reduce battery life.
When not using the camera, remove the battery.
If the battery is left in the camera for a prolonged period, a small amount of power
current will keep being released, resulting in excess discharge and shorter battery life.
Store the battery with the protective cover attached. Storing the battery when it is fully
charged may lower the battery performance.
The battery charger can also be used in foreign countries.
The battery charger is compatible with a 100 V AC to 240 V AC 50/60 Hz power source.
If necessary, attach a commercially available plug adapter for the respective country or
region. To avoid damage, do not connect to portable voltage transformers.
Check battery recharge performance, as needed.
Press the charger's <
recharge performance, as indicated by how many of the three lamps are lit in green.
: Battery's recharge performance is good.
: Battery's recharge performance is slightly degraded.
: Purchasing a new battery is recommended.
If the battery becomes exhausted quickly even after having been fully charged,
the battery has reached the end of its service life.
Check the battery's recharge performance (
> button during charging to check battery
) and purchase a new battery.
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