A "quality" 2.4 ghz phone will not interfere with a 802.11b network.......they are on seperate frequencies...both in the 2.4ghz range. It's much easier to say "2.4ghz phone", instead of "2.41345-2.41203ghz phone".
Far as complaints about battery charge capacity...... any and ALL Nickel based batteries need to be conditioned when new, and cycled every month or so. This includes Ni-Cad and Ni-MH batteries. Use google and search, lots of great info out there. Yes some phones just such da juice, but others need just a little work. Case in point, my Panasonic phone after the initial 15hr charge, only lasted 1 hour on intercom mode. After power cycling it a few times, I now get about 4.5 hours. (I use intercom mode so not to tie up the phone line).
My $.02
Oh, BTW, I wouldn't buy this phone. I took a look at it during lunch....yuck. big, bulky, cheap feeling by today's standards. But good for a garage phone I guess....spray paint it orange so it's easy to find. heheh