Maxcom MM824 User Manual page 96

Never leave the charger connected longer than 2-3
days.
Never keep the phone in excessively hot places. High
temperatures might negatively impact both the
battery and the phone.
Never use a battery that is clearly damaged. Doing so
might cause a short circuit, and might damage the
phone. Check battery installation for proper
polarization.
Leaving the battery in excessively hot or cold places
will reduce the battery life. The recommended storage
temperature range is between 15°C and 25°C.
Installing a cold battery into the phone might cause
the phone to malfunction and might damage the
phone.
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