Verykool i315N - Manual (Page 11)

2.3 Battery
The initial state of battery charge has about 50% of the electricity. The first time to
charge you should completely exhausted it (depleted battery will not turn on it) and
then completely filled it; have it completely run out before the second charging; so
after three consecutive cycles, the battery will be easier to achieve the best condition.
Note: The battery is welded one. Do not arbitrarily remove it under normal
circumstances.
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