First of all as to a mention in a previous post it does work on ATT but only at EDGE speeds not 3G or 3.5 G. I dumped ATT and now use Simple Mobile which works on the N900 at 3G or 3.5G depending on the areas reception or location and it works quite well. As far as 4G is concerned I believe it has been mentioned in the past on these forums that N900 does not support 4G. The stock batteries are 1320 mah and most marked higher are usually BS with a few exceptions like the Scud ( see battery info topic by "dr_frost_dk". As far as Verizon it they use CDMA so the N900 does not work on Verizon 's network as the N900 is GSM. ? Return the box for a rebate ? Buyer beware of N900's for sale and the claims made by those selling such. I have two N900's bought new which I still use but you should really think about finding a more up to date phone that is still supported by the manufacturer. Good Luck !