Never take the days of flying without a recharge to heart. Always check your batteries with a loaded voltmeter at the start of the day.
Here's what I do. I'm running 9 servos I know that I can probably get 2 days of flying with a cushion on a charge. Check the batteries with a 1 amp load recharge at 7.1 volts.
now if it's the beginning of the day I'm going to recharge before I fly. But if I check it at the end of the day and I'm at 7.1 I'll fly that last flight but keep it short.... You'll get the hang of it. Once you go gas you never go back.....good luck