[Desire Accessories] nawoa:
A small update to my previous post... I'm now at 32 hours, 38 minutes uptime, 4 hours 44 minutes awake time (screen on). Battery just reached 60 percent. Stock battery.

Remember when you made the choice to buy an Android, you were in effect saying you wanted to have a highly customizable miniature computer. Just like when you customize [insert your desktop OS of choice] to suit your taste, you need to configure your phone in order to get what you want out of it - namely, better battery life than with the standard settings.

HTC's goal with the Desire was to have a showpiece, it runs very fast and it looks good doing it. But they designed it with frequent charging in mind. Since most of us here, I imagine, would prefer to charge less often, we just need to configure the phone appropriately.

If you want a guaranteed solution, try this:

- Install NextSense rom (it's free, latest version right now is 5.3 AFAIK, I'm currently using 5.2 still)

- Install JuiceDefender - it's free on the market and its default settings are, for a change, very intelligent and effective.

- Install SetCPU - You can get it free on this forum. Set it to "interactive" mode with a bottom speed of 245 and a top speed of 806 to start with. The default is 998 at the top, but 200 mhz doesn't make a big difference in this case except to help battery life a bit. Once installed, add a profile for "screen off" which sets the phone to "powersave" mode. This will keep it running at the minimum clock any time you're not using it. Nothing running in the background while you're not even using the phone requires more than the minimum CPU speed.

- Install the Brightness Widget by Curvefish. It's free on the market. Put its widget on your desktop and keep your screen brightness at 25% while you're indoors. 15% is what I use, but 25% is one of the presets so it's a bit easier. I have an SLCD display so the brightness I get on auto might just be different from what OLED gets on auto, I don't know, but in any case for me it's way brighter than it needs to be.

- Set your screen timeout to no more than 2 minutes

- Make sure any apps that sync data do so in a reasonable interval. +/- 15 minutes won't ruin your day for most things.

- Under Wireless & Networks, set your phone's connection to WCDMA-only (3G-only). For many people this results in an increase to both signal quality and battery life, since it allows your phone to only run one radio at a time, making a significant difference. If it doesn't work for you, it's as simple as turning it back to the default setting.

- Disable haptic feedback and see if you mind the difference. Making all those little vibrations takes power too.

- Finally (obviously) don't run a live background, but you probably already know that.

Doing all of the above takes an hour or maybe two at most to set up and the difference in battery life is tremendous. It's simple to do, I worked out all of the above on my own and I've literally only had the phone for 4 days now I think, never touched a smartphone before in my life let alone an Android.

Give it a try, you have nothing to lose, and it will probably save you needing to buy a battery. Or, if you still buy a double-capacity battery, it'll mean you can run for like a week on a charge. :)

edit: also make sure to get the latest version of the radio driver, I don't have a frame of reference for comparison since I updated mine right away, but apparently it makes a fair bit of difference and probably gives you a more reliable cell signal in the process.

In case you think I'm exaggerating, here are some pics I just took.