As often as possible. If I can do a front-load of reading data and only have the data radios on for a fixed time (ideally, over wi-fi), that's going to be less

As often as possible. If I can do a front-load of reading data and only have the data radios on for a fixed time (ideally, over wi-fi), that's going to be less of a battery drain than the on-again/off-again of casual browsing. Not to mention that it dramatically improves the reading experience to not be waiting on inconsistent data rates and server speeds during my reading time.