well its not so much the batteries themselves - I could care less - its more an issue of the battery door and the ubiquitous "Tawd fix" for the band/pin issues on all the foretrex units. On the 201, we take liquid nails and "glue" the band to the unit so when the pins do pop out of the housing, the unit isn't lost to Neptune. On the 301+, you'd have to glue it to the battery door, which would make taking the batteries out quite ... difficult.