Battery + AC Adaptor OR Mini Dock?

[Camikazy]

So I have the choice of replacing the extra 6-cell battery and AC adaptor that come with my thinkpad for a mini-dock. Is this a good idea? I don't see myself using the battery so much that I'll need to replace it within a year, and the mini dock comes with a built in adaptor anyways. The main reason I wouldn't want the battery is that I heard they go bad if you store them for a while anyways, so it would seem like a waste to me. Don't really need the dock, but would be nice to have. Please help me out here!

Thanks

[daeojkim]

If you do not carry around your laptop a lot and use it more than 3 hours at a time, then get the minidock.