Look likes i need to post a link to d  previous version as well..
Ok 1stly .. Wat is ur set? Ori or ap? Install a nokia energy profiler and check ur energy usage plus check ur battery capacity.
2ndly.. Wat ur usage? Wat software hav u installed? And wat version r they now..?
3rdly .. How do u use ur E71? Duration of use.? Wat software or application u r running all d time.. Wat u mean ur bat life got shorter? Ur previous firmware giv u a 5 days n now ur new 1 giv u 1day?
4thly.. Wat to do? Reformat or hard reset ur set after d upgrade. Reinstall everything..stop playing around with it more often .. Sometimes is all bcos of us when v got something new.. V tend to play it more often than v do b4 bcos u wanna know wat is d improvement and upgrades done.... Then v said it last shorter bt it is due to d chg in our usage patern...
Finally.. So wat can i do to resolve tis? like i said install nokia energy profiler and check ur bat capacity and usage.. If ur usage is above 0.05w dont expect it to last more than 3 days..  Upgrade ur garmin version to 5.04 and above. Turn off background programmes. Set ur set to gsm only if u r not a 3g user.  Well tats all i can think of.. Want more info ask google or wait for others..

blablasheep : im using v300 and yes the battery life is significantly less than v200. however it still lasts me about 1.5 days tho

ps : is it really firmware issue? cause i notice all phones ive used that the early stages battery life is very long but as it gets older the life also shortens righT?

some shops tell me its cause sometimes when we leave the phone to charge and over-charges, it damages the battery as a whole. can anyone enlighten me?

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Added on August 31, 2009, 2:57 pmone other question : nokia energy profiler does what? allows us to see the life of the battery? or usage?