Haier CG 100 User Manual page 4

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.
Please remove the battery only after the phone is switched off
normally, otherwise it could cause unpredictable damage for the
phone.
Only qualified personnel should service the phone or install the
phone in a vehicle. Faulty installation or service may be dangerous
and may invalidate any warranty applicable to the device.