Canon MARK IV User Manual (en)

Charging the Battery
If all three Charge level indicators blink in green, it means that the 
battery’s internal temperature is not within 0°C - 40°C / 32°F - 104°F. 
The battery will start recharging when the internal temperature is 
within 0°C - 40°C / 32°F - 104°F.
If all the Calibration (discharge) status indicators blink in red or if all 
the lamps blink in red and green (including the <CAL/CHARGE
lamp), remove the battery from the charger and take it to your dealer 
or to nearest Canon Service Center.
Also, if a battery other than Battery Pack LP-E4 is attached to the 
charger, the lamps will blink in red and green (including the <CAL/
> lamp) and the battery cannot be recharged.
All Three Charge Level Indicators Blink
The charger cannot charge any battery other than Battery Pack LP-E4.
Battery Pack LP-E4 is dedicated to Canon products only. Using it with a 
non-Canon battery charger or product may result in malfunction or 
accidents for which Canon cannot be held liable.
When two battery packs are attached to the charger, the battery attached 
first will be charged first, then the other battery will be charged.
Although one battery can be recharged and another calibrated at the same 
time, two batteries cannot be recharged or calibrated at the same time.
For battery calibration, it is best to do it after the battery is nearly 
exhausted. If you do the calibration with a fully charged battery, it will 
take approx. 12 hours to complete the calibration and the battery 
recharging (approx. 10 hours to discharge, and approx. 2 hours to fully