Good point, thanks. I usually make sure I'm home before the last red LED has been 'used up', and only 'reset' if I'm in need of assistance.
As an observation, I find that the two green LED's usually go within 2-3 minutes of using a fully charged battery, and the yellow goes out about 5 minutes later, followed by the reds about 10 minutes after that... This always appears to happen. Perhaps my battery is becoming poorer in quality. After all, it is a car battery, yet it seems to tolerate constant charge/discharge/charge/discharge etc.
I should point out that I'm becoming more concious of pedalling more, and using the motor less, to help offer me a better range. It does seem to make a difference when I only use the motor in short bursts. It's surprising how far you can 'roll' or 'coast' without applying any power or even pedalling. Almost as if it were perfectly balanced! Super.