Making the battery last MUCH longer

[Mid]

I still own an HP iPAQ. Granted it's getting on a bit but I can do everything the Orange SPV M2000 (Blue Angel) can, except make phone calls. It was a great little device and one of the best things about it was the battery lasted ages.

Granted it doesn't have to keep polling the radio signal every few seconds but there is one way I think that battery performace could be improved and that's by making the screen less bright.

Right now I find the screen is way too bright at night. I play games and read on it in bed.

Is there any way of programatically making the brightness levels finer grained? WM5 has 10 graduations whereas the iPAQ has about 30.

Through this one change alone, I know I could get about another 2/4 hours usage out of my Blue Angel.

Anyone (Helmi?) know if this is possible by simply increasing the number of divisions in the brightness slider?

[Mid]

Isn't this just a change of a variable in the code or does the hardware fundamentally not allow it?

[Percz]

Looking though the registry there is a reg value for the brigtness levels at..
HKEY_CURRENT_USERS/ControlPanel/Backligh/

[ACBrightNess] and [BrightNess]

At default, the maximum value of the BrightNess settings can be 10, the lowest 1, with any other number higher or lower apparently turning off the brightness. You can adjust the scale of the brightness levels, so you can have 30 diffrent levels of controll by editing the [DefaultACBrightNess] and [DefaultBrightNess] values to 30, but this doesn't work too well on my device and value 1 is just as bright as it was before.

One extra little thing though, is that on the same registery folder is a value [QKeyLedTimeout] which controls the timeout of the blue lights behind the slide out keyboard, in seconds. I've set this to 30 which seems to be better then the mear 10 seconds you are normally given.

[Mid]

Thanks for that Percz

I'm going to download a registry editor from somewhere and give it a shot.

Did you work all this out by playing around with the registry?

[Mid]

I found in the same folder

HKEY_CURRENT_USERS/ControlPanel/Backligh/

the two keys MaxACBrightness and MaxBrightness. I set those to 30 and now I've got 30 graduations in the slider but only the first 10 work.

I guess there must be another two keys somewhere that set the actual low brightness and high brightness values.

I'll keep digging around and see if I can find something.

[PPCNUT]

Well I have a HP Jornada 720 Handheld PC and it is 6 years old and still has the original battery in it and I find it lasts about 7 hours easy and I use it every week or so now but before I would be using for a couple of hours a day and it just keeps going a reset every few months but other than that it is fine. With the BA reset it 3 times a day, carry a extra battery just so it makes it through the day and then you still have other problems.