Running HTC Wifi Sharing 24x7

[beestea]

Has anyone ever tried to run HTC's wifi sharing software for an extended amount of time/days? I've used it alot on my Touch Diamond and find that eventually (3-4 hours) it heats up the phone/battery and then the battery stops charging resulting in the phone shutting off.

I am trying to find out if anyone has used a CDMA/Sprint phone to do this 24x7.... I know its a strage request but I am trying to give my old Sero plan to a relative who will only use it for Data. This is the only type of broadband they can get where they live and not only that but I will need to position the phone (and maybe use external antenna) in a specific spot for a consistant signal.

Maybe there is a phone I could use off of power supply only with no battery? Anyone else do something similar?

Obviously the proper way to do this is via data card and 3g cdma router, but that route will be about $24/month more, plus equipment costs.