2.5G just means that EDGE is available. As long as you do not make actual EDGE data "calls" it will not use more power than 2G.
(Other than 3G which always uses more power)
And, no, there is no way to disable the .5 since it only signals EDGE is available...

im not sure if any one is reADING ... I JUST MOVED HERE... AND NOW I AM Having bATTERY ISSUIES

Are you 100% sure that this is the culprit for your extra battery drain, as i've never noticed any difference between the 2 & 2.5

What else have you installed lately?

People are reading, you're not asking the right questions. Look at the title you gave this thread.

'.5' has nothing to do with your battery problem. Check to see what processes are using a lot of CPU resources and draining the battery. To do it either install Conky and use that or open a terminal and type 'top'.

ill tell you a solution buy a mugen battery that'll fix your problem

i agree with casketizer. the fone just shows the 2.5g availability and doesnt use any extra power than 2G. My fone shows 2.5G too and battery works for minimum a day with wifi usage as well as some hours of music playback.. you need to reflash your firmware and emmc ..that should defo solve ya problem.. if it doesnt ..its time for a new battery !

you can also try boostn900 script, for better battery ..
http://talk.maemo.org/showthread.php?t=63997

Reflashing should not be necessary, especially the emmc as that erases everything stored there. Better have backups!

I've never flashed my N900 and probably will never need to. No, all he needs to do is find the offending process and fix it or simply uninstall the software causing it.

for some its a quick fix to annoying problems, i do it every now and than with a prior backups ofcourse

maybe the signal was stronger at the previous location. Low signal at your current location means that the phone has to ramp up the power of the antenna to get the same performance. that could explain the battery drain.

edge adds further modulations that the radio stack can use. If there's no data moving, it uses exactly as much as 2g.