Unless you are bringing the TB farther away from its goal then there is no problem bringing it with you on the trip. The TB guidelines do say if you are keeping the TB longer than two weeks then just alert the owner by e-mail. Also, a TB does not belong to the cache so you don't have to trade anything for it, unless the cache is a TB hotel then you need to leave another TB. I do like batteries left in caches because my GPS uses them up fast. (but please leave them in a sandwhich bag)
Hope this helps,
Patty556