Battery life on the G1 has been an issue since the release. Well I have been playing with a G1 for a while now and have some tips to help with the problem. I feel the problem is not with the phone, it’s with how YOU use the phone. I have the same problem with my Blackberry Curve when I use it like the G1. Turn on all the bells and whistles, and your battery like will be shorter on ANY device.  It is like driving 90 miles an hour on the expressway and expect to get 65 mile an hour gas mileage. Not going to happen…  SLOW DOWN and you will get better mileage.

Slow down your G1 until you need the speed, and will extend the run time of your G1.

Download Toggle Settings from the Market.
Download Power Manager from the Market. Make sure you turn on the monitor.
Download Watts. This will let you monitor the battery life and see how these steps improve G1 life.

Make sure you condition “drain” the battery 2 to 4 times completely. Yup let the phone die a slow death.

The battery does not have a memory, but it does need to be drained every few months.
Then recharge it until a few hours after it says that it is full then it will recalibrate itself and the battery will now “know” how much power it can really hold.

Turn off all the following until needed. Use either the Power Manager or Toggle Settings.
“Use only 2G networks” EDGE. GPRS is too slow, but does seem to check email just fine.
The phone tries to reach a 3G network even if there is no reception of 3G.
Switch off Bluetooth
Switch off GPS
Switch off WiFi
Switch off Location
Screen Brightness 0%-25%
Screen Timeout 1 to 2 minutes.
Remember to hit the END button to trun off the screen when done. This will turn off the screen.

Also make sure you use the power charger that was shipped with the phone, and not any random Mini-USB “blackberry” charger.
I found that my Blackberry charger heated up the battery and took longer to charge the battery to full life.

Some apps also kill the battery life.
Facebook, MySpace, and other applications that checking to parent site on the internet for data synchronization.

Still not enough? Well here is a MORE POWER option.

For the road warrior you can buy a mobile external battery.
http://www.pcusacorp.com/product/YP-M8565.html

http://www.newegg.com/Product/Product.aspx?Item=N82E16882454001

For an internal Solution there is an 1400mAh Extended Life Battery. This will set you back about $50.00.
http://www.seidioonline.com/ProductDetails.asp?ProductCode=BASI14TMG1

http://www.crunchgear.com/2009/01/01/review-innocell-1400mah-extended-life-battery-for-t-mobile-g1/