Just seen your reference to battery life.... If you are using the external anttena, this is powered, so it may eat batteries a bit. I always load fresh ones before doing a cross country. A friend of mine has bought rechargeables, and these seem to do the trick as well. I have used mine for about 2.0 hours since putting in the latest set of Duracells.
Also, on another note, even if you dont fly much, its a good idea to get the unit out one a week or so, and allow it to capture satellites so that it can "fix" its position.
Otherwise, it will take AGES to acquire all the satellites and fix it position when you have the engine and Hobbs meter running!
Cheers