If you trust your mod's charging circuitry as much as you trust the charging circuitry on your cell phone, cordless power tools, electric razor, etc then you should sleep well. It is true though that most battery failures occur during charging and that rate includes all of the myriad of portable, rechargeable devices we take for granted these days.
Your real question is: Do I trust this device to behave itself, knowing that it was made in a country not exactly renowned for exacting quality control standards?