I learned oh so long ago... to flash with a full battery and NOT touch the calibration. But if you have... This is what I have learned (I'm an Automotive tech specializing in electrical and ECU/CPU/AMP repair) kill your battery until it shuts off.. leave it off and charge it until it's full. Leave it plugged in, power on into CWM recovery (OR battery calibration app), unplug the charger, and immediately clear the battery stats, then if I remember correctly restart normally, and let your battery drain normally until it shuts off. and then charge until it's full before powering on. (I learned that on the first charge/drain cycle after calibrating, to not use the phone, and let it drain as slow as possible, in airplane mode) the next charges would last longer that way. This was on the Samsung Admire though :/ I have never had issues with the esteems battery that wasn't due to apps or bloated ROMs
Lithium Ion batteries last longer when used/cycled in that way.
They also HATE being at 100% charge. The electrolyte is very acidic at full charge (nearly no acid in a dead battery) and in LithIon that acid eats the annode and cathode plates. reducing the Reserve capacity of the battery pack over time. Manufacturers know this, that is why LithIon packs are shipped (most of the time) at %50 charge. Crazy bastard packs HATE being at zero volts, and tend to not accept a charge after true zero. (most packs have a circuit built in to shut down before that, this is why camera flash can reboot a phone that has a lowered b battery reserve capacity)
Best way to make battery last. The Dock. It charges the spare pack faster than my esteem (running light Rom/apps, with below 95MB ram usage) drains its pack.
Androids somehow like battery pulls, and switching between two packs every other day has made my packs last a year with minimal loss in reserve capacity. (the ability to hold a charge, and supply it over time)
I used to struggle with these packs. Cycling and storing them is different than the Lead/acid batteries in Cars.
here's a really Good link with the details if anyone wants to check it out
How to Prolong Lithium-based Batteries - Battery University