I've been told that a row of batteries can look a bit like ammunition. For that reason, it seems better to put them in cabin baggage, as screeners can then pull them out to look at them if they need to. Putting them in checked baggage might increase the risk that the bag is inspected so thoroughly that it misses the flight.
Of course, in the topsy-turvy world that's run by the TSA, this general advice might not hold true.