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I have had mine stay at 100% over night on a regular basis. This is with charging in later afternoon and no use till am.

Mines jailbroken. I charge mine when I get home from work and unplug it before I go to bed. Doesn't drop a % at all.
 
If charged before bed and unused, it will still be 100% (first 1% seems to last a lot longer, 30 mins of wifi before it's 99%)

Otherwise 1-2%
 
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