Two days ago I updated my Nokia Lumia 800 to the latest Windows Phone version 7740. The day after, I tweeted at about 6PM how amazed I was at my Lumia 800 still holding 74% of the battery after almost 8 hours of use. The change log in the Mac Connector did not say that the 7740 update would improve the battery life, but the official French Nokia Developer Twitter account has tweeted that the update does indeed “improve the autonomy” of the Lumia 800.
Reports of the Lumia’s battery performance have been very mixed. Some users report that their Lumia will die within 6 hours, others say they can go a full day of heavy use. Personally, my Lumia 800 is able to hold a charge for a full day of heavy use. As of now, my Lumia has been unplugged for 3 hours of heavy use and I have 90% battery left. At this rate, I have another 27 hours of battery life. Either way, updating your Lumia 800 is advisable even if it does in fact, not improve your battery life. Just plug it in to your Zune or Mac Connector and follow the steps. Tell us whether 7740 did something to your battery life or not!