hi koivjann,

Thanks for the explanation, i'm not a normal user, i was checked my email/browsing every 5 to 10mins, 99% my life communications all depends on phone coz i'm always mobile.

Wow sounds like you are very demanding on the battery. I am interested to know what your current mobile device is that can keep up with your demanding needs.

The Nokia E71 can handle that use case absolutely no problem. It will last the whole day and perhaps half of the second day too.

For example, on 3g using Nokia email with constant connection, 9am -> midnight will loose about 30%-40% battery. With Edge, loose about 20% battery. I still don't understand why Nokia couldn't squeeze in the same battery but made space to hold the sylus!

I would be really curious to know how the n900 compares with E71 with similar usage (e.g constant email, always on IM etc etc)

I am not sure-- he seemed to imply that 14 to 16 hours of heavy use was not enough for him. So I wanted to know what his device was since it seemed unusual.

Wow the E71 gives you 14-16 hours of "heavy use" I truly am amazed. To me heavy use means browsing over 3g and multi-media, and listening to internet music. Not just checking your email once every hours or two.

Yes, the E71 can give you 14-16 hours "heavy use" 3G browsing, internet music, email. The E72 is supposed to be 15% better and also longer battery for playing music. The screen is only 2.4 inch though so its tough to do a comparison unless it involves limited screen (checking emails, music, IM online but not much chat etc)

I truely believe it (E71 or E72) is the longest lasting smartphone(with keyboard) in terms of battery usage on the market. Period.

i'm nokia fan, i was using communicator for many generations, after a while i jump into win mobile 3, keep on hangs, threw it and tried HTC but very dissapointed with the battery, i was changed to iphone 3g, also a same problem, i threw it and replaced with e71, i'm happy with that and thinking to change N900, hope this phone can me happy

While this is partial true, there's also the fact that in a LCD only pixels with a color variation have electrical current running to them, anytime there is a true black color( 0 0 0) on a TFT LCD there would also be no electrical current entering the Liquid Crystal layer anywhere there is black to realign the pixels and the more True Black pixels per row the more energy savings you see. Though the power saving from that would be negligible.

Interestingly, it appears that battery life of the N900 is reduced without a SIM card. This may explain the disconnect between what I'm experiencing with my N900 and what others are seeing.

From that link, igor says:Hopefully this will be fixed, as I imagine some people will want to run this SIM-free.

Hi,

I've read in several places that the battery is drained more quickly on 3G than on Wi-Fi, and several people say they don't use the 3G so much because they use their home Wi-Fi, or free Wi-Fi hot spots. (If you can find them! There are hardly any where I live, everyone uses WPA).

But what I couldn't get from any of the many messages about it is this:

Is that battery drain from just being connected to a 3G mobile network, or is that active use, sending and receiving lots of data, e.g. for web browsing?

When people say they are "not using 3G when they're in Wi-Fi range, so the battery lasts longer", does that mean leaving the mobile network completely (so you can't receive incoming calls), switching to 2G, or staying online on 3G/HSPA but without using packet data?

And if the battery life is good when on the 3G voice/SMS network, but not actively using packet data, but significantly poorer when packet data connection is active, does that forbid applications like IMAP IDLE (push email), Skype and IM, or can they be made to work while letting the packet data connection go inactive, as long as you're not sending anything and nobody is sending you anything at the time? (Even if you had to use a proxy server to change protocols - any method would be fine. I write proxies for fun ;-)

I ask because the Three network in the UK (and maybe elsewhere?) does not provide even voice service over 2G. You must use the 3G voice/SMS connection to receive calls and messages.

Well, actually you can connect over 2G, but if you do it consistently, they'll block the handset because they handle 2G using a partner network. Their own network is 3G only.

I'm a bit worried that if I'm on a trip for a couple of days without power, and I disable all data applications, I might still drain the battery "quicker than using Wi-Fi" (implied by many articles) just from being connected to the 3G network enough to receive incoming calls and SMS notifications.

So if someone could clarify if the battery life is good when not using packet data, but registered on the 3G voice/SMS network, I'd be most grateful. Thanks :-)

(I distinguish "packet data connection" from "on the 3G network" because Symbian phones seem to).

If someone tells me that the battery life is good even when running mostly idle IMs/Skype, having mostly idle online presence, that'd be extra nice :-)

If online presence requires packet data connection, but there is some hack whereby that can be avoided if you're almost never sending and receiving packets - after all, you can receive SMS notifications without a packet data connection - that would be rather interesting.