Haier I50 User Manual page 77

Safety Information
strength on the cellular network and the parameters set by the
network operator.
Battery charging time depends on the remaining battery charge,
the type of battery, and the charger used. The battery can be
charged and discharged hundreds of times, but it will gradually
wear out. When the operation time is noticeably shorter than
normal, it is time to buy a new battery.
If left unused, a fully charged battery will discharge itself over time.
Extreme temperatures will affect the charging capacity of your
battery: it may require cooling or warming first.
Do not leave the battery in hot or cold places because the capacity
and lifetime of the battery will be reduced. Try to keep the battery
at room temperature. A phone with a hot or cold battery may not
work temporarily, even when the battery is fully charged. Li-ion
batteries are particularly affected by temperatures below 0°C
(32°F).
Use only approved batteries and chargers. Disconnect the charger
from the power source when it is not in use. Do not leave the
battery connected to a charger for more than a week, since
overcharging may shorten its lift.
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