Folks,

I am writing this in an attempt to help everyone out there that is experiencing poor battery life on their Nokia N900. This guide is meant to be used at your own risk and I shall not be held responsible if you inflict any damage on your phone, yourself, your pets, your significant other or any other entity related or not-related to you.

Introduction:
I have been waiting for a device like this for the past 5 years. This is the first device in North America which allows you to make voice calls over Skype and other VOIP applications. I work in as a Sr. Linux/Unix Systems Administrator and for me having a device with so many features and power is absolutely a must.

I was very disappointed, like some of you perhaps, to find out that my brand new Nokia N900 could barely offer 6-7 hours of battery life under modest use. I was on the verge of returning the phone to the Nokia store in Chicago where I bought it and get my money back and revert back to my android devices.

It was so bad that the phone will drain 90% of its battery over night sitting on my night stand on stand-by!

It was not until I did some research and I managed to "tune" my phone to increase almost THREEFOLD the battery life.

Replace your SIM card:

As it turns out, and old SIM card will have a lot of scratches on its pins. Some of the may even be bent inwards or otherwise damaged. I was using my original SIM card back from 2004 when I first became a T-Mobile customer. The SIM card was really in poor shape.

I visited a local T-Mobile store after talking to T-Mobile engineering support (not the regular customer service) and requested that my SIM card be replaced. Of course, this was done free of charge. It turns out that the SIM cards are not designed to last more than couple of years and they really should not be taken out of the phone frequently as this damages the pins.

Long story short, old SIM cards "leak" power due to bad contacts and increased internal resistance.

EDIT: In addition, other users have mentioned that depending on their age, different SIM cards operate in different voltages (5V, 3V, 1.8V). The N900 has support for legacy SIM cards which means older SIMs will require more power.

Adjust screen brightness

I have mine set on 2 out of 5. Majority of the time I do not spend outside so screen brightness is not an issue for me.

Remove Widgets from Desktop

I found out that the OMWeather and Foreca widgets eat up a lot of CPU cycles and therefore battery power. Any widget that refreshes the display and its status will drain power.

Instead, use icons and shortcuts. I have a shortcut to Foreca weather application. I only need to look at the weather forecast only twice a day and only once on my cell phone.

Also, the more widgets you have on the desktop, the more longer it will take phone to render their images and refresh everything.

Adjust refresh frequency on your email applications:

I have total of 3 mailboxes that I keep track of on my N900 and one of them is Exchange mailbox. I have set the mailbox refresh frequency to 1 hour.

Ask yourself one question: Do you REALLY want to be nagged frequently by work email when you are outside of work? Fetching email once per hour is more than enough for me.

Trim your mailboxes

The more folders you have in your email accounts, the longer it will take for your N900 to refresh your folders. Same goes for the number of emails per folder. Having 20K emails sitting in your Trash folders on your IMAP mailbox server is just a waste of time for your N900.

Disconnect from Wi-Fi, 3G and other wireless networks when you are not using the phone

I am pretty sure that you don't want to receive IM chats on your N900 at 3am in the morning. So, disable data networks during the times that you sleep. You will still receive phone calls and SMS messages in case of emergency.

Disable your Bluetooth when not in use

I use my Bluetooth only when I am in my car so that I can accept and make phone calls from it. Unless you ABSOLUTELY have to have a bluetooth head set, using regular earbuds will always be a more power saving option.

Adjust settings for notification light

I have removed the notification light when the device is on. Having the LED blink all the time when the phone is powered on is just a waste of energy.

I have all other notification lights enabled.

Adjust your profile settings

* Remove vibration notifications when IM is received. Do you REALLY need your device to vibrate every single time someone sends you an IM?

* Adjust the volume for your notifications. Setting the volume to the MAX for your notifications is perhaps unnecessary.

* Select shorter ring tones. This way the device has to power on the external speaker for shorter period of time. Energy is saved this way.

* Disable the vibration feedback for the screen. Like disabling vibration for IM notifications, if the vibration motor is triggered with every finger press, that's going to drain battery

Summary:

With the above mentioned changes, I was able to increase the battery life on my N900 over THREEFOLD without loosing any of the functionality. I have my GPS enabled including Network-based positioning. The device is smart enough to keep the GPS module on stand-by until an application requests it.

With those settings, my battery was showing 100% charge after 8 hours on my night stand being on stand by. I listened to music while commuting on the train for 1 hour while exchanging some IM and browsing the web over 3G. By the time I get to work, the battery went down to 90% of charge.

Over the past 3-4 days, I can say that during a normal work day and normal use, my phone uses about 40-50% of its battery.

Good luck everyone!

I have a similar configuration on my Symbian phone and it does show a difference. Less 3G use = more battery life.

wow thanks for the nice write up...

nice tips......

regarding your first point:
i will definitely keep this in mind, although on my samsung jet i dont have any battery life-issues. btw, my sim-card is around 6-7 years old now. its the old card my father used in his old phone.

regarding your other points:
- check [x]
- check [x]
- check [x]
- check [x]
- check [x]
- check [x]
- check [x]
- check [x]

all these points obviously also are valid for other mobile phones. i basically have things set like you said or in a similar way on my jet.

so i am very positive that my n900, when i receive it, will last long enough to keep me happy.
still i am going to bookmark this thread just in case i need a list to check on what i need to do when my battery life is unsatisfying

Thank you for a nice set of power tips. However, it is a bit inconsistant and biased.

You can save even more power by leaving the GPS and cellular radios off except when you need them. Conversely, wifi is also optimized to conserve power when it is not being used. I leave wifi on all the time without problem. I have not put a SIM card in yet because I have not yet found a way to have the cellular radio off and the wifi on.

Please do not assume that every n900 user needs to have the phone part on all the time. Also, the cellular radio is a far larger power hog than wifi. It is not necessarily a battery life problem to leave the wifi on 24/7 and I suspect leaving GPS off except when needed
would give longer battery life.

Thank you very much!

Your guide should part of the "N900 owners guide"

Actually having the cellular radio on doesn't drain that much power. The big power drain when data is actually being transmitted: during a phone call or actual data transfer on a data connection. When the cellular radio is in standby mode, it power drain is quite modest. You can tell that from the battery life specs of cell phone. They have two measurements: standby and talk time. And notice the huge different between them.

On my iPhone, I usually leave 3g off, and activate it when I need to surf. Lately I haven't, and the powerdrain difference is noticable. But I don't really care, since I'll only be using the iPhone for a few more days

I've somehow missed seeing how I can enable/disable vibration for individual notification types. How may that be accomplished?