I see what you mean, but I still think it's more down to luck what you see as percentage in the morning. Let's say it takes two hours to charge the phone to 100% from 20%. You go to bed for eight hours. That still leaves 6 hours to discharge/charge the phone with or without background connections. It will certainly not go six hours with just 2% even in PSM.

Battery level is just a number, 93% is almost as good as 100%. It's not an exact science...