Any version of OS.... Eclair, Froyo, Gingerbread, etc... Any device, single core, dual cores, extended battery... It still all comes down to device management/house cleaning as I like to call it...
We all have our own styles of using our smart phones but sometimes we do have to sit back and take a look at what we really are doing. Email accounts getting polled often, mass amounts of useless junk mail coming in, social media running, videos, music or music players, bluetooth left running/searching for connection all these and many more will all put a big hit to your battery.
Stay away from any 3rd party task killers as crutch to take care of things, they do more damage than good...
Chargers... Auto/Home check the amp ratings on the charger... If they aren't pushing out enough juice and your using the device or its sitting idle doing your normal email polls and stuff it maybe just enough that its taking juice quicker than the charger can provide. That is where many of these couple dollar deals come in for chargers... Great buy but they don't charge at an efficient enough rate to be in use while charging...
Many variables involved, just really take the time to look at your setup and try to eliminate possibilities, shut some stuff down and watch the result over a few hours...