Originally Posted by HuhWhat
Incorrect. That pcb board has a computer on it and a battery charge controller. These li-poly batteries require very controlled charging. The charge controller on the helicopter charges the battery until the charge voltage across the battery reaches about 4.8 Volts. It appears that if the no load voltage across the charge terminals increases much above 5 Volts the helicopter can be damaged. To check any charger just plug it into an outlet and measure its' output voltage. If the voltage is much over 5 volts it may damage the heli's circuit board.
I know there is a overcharge board on the LiPo, of course when this cuts off from the charger if the charger is unregulated it would rise above smcharger voltage, I have charged a a S107 cell from the USB charger without it being in the heli, charged as normal with no problems so I really doubt there is in charging circuitry in the helicopter.