I had a Hyperion Super Duo that did not stop charging once. Luckily I was sitting there, and caught it after the packs voltage went a bit higher than it should have (still charging away at full bore, never even dropped the rate to balance/finish.) All the charger settings were correct, and had been for months. Power cycled the unit and sat there and watched the next pack that DID stop correctly. Things do sometimes go wrong for no apparent reason, leaving a lipo completely unattended is risky at best.