I never know what to put in for the subject.
Hard drive players don't skip easily at all. You'd have to be in an earthquake for 20 minutes to get it to skip. The nature of compressed audio files like MP3s is that since theyr'e compressed and "encoded", they have to be "decoded" in order to be played. Unlike a CD player, which reads raw data from a comapct disc and outputs it straight to your headphones, compressed audio, once it's read from the hard drive, needs to be digitally processed first by a computer. Memory is required for this, in the form of memory "chips" like RAM, independant of the hard drive. This memory also buffers the audio that has already been decoded, so what you hear from your headphones is actually coming from the memory and not the hard drive. Most hard drive players are built with enough memory that they can decode and store the entire music file in memory, and since this memory has no moving parts, it can not skip. Therefore, barring a faulty product, you should never hear any skips in any song. Lawnmowing shouldn't harm your listening experience, unless you accidentally get your player or your hand caught in the blade. That would suck.
As for battery life, check the cNet reviews for actual battery life of the players you're looking at. You can also check the company sites, but their claims are seldom accurate. I don't see why you'd ever need to buy extra batteries, because even the lowest battery life is something like 6 hours. So unless you're flying non-stop to the middle-east on a regular basis, which I don't know why you'd be doing since they have all the terorism and stuff, you should be fine with the included battery. If you need exteded life just look at some other players. I have a Sony HD5, 40 hours claimed life and 24 hours tested by cNet. I recently took it on my drive from long island, new york, to southern Maryland, a 5-6 hour trip, had the player going the enire time, and the battery guage didn't even make it to the halfway mark. I think cNet said that the Zen had a pretty insane battery life as well, something like 25 hours, not sure though.
Charging times are generally around 2 to 3 hours for a completely full charge, but an 80% charge, which is usually considered full since that final 20% takes like double the time to trickle in, takes something like an hour to an hour and a half.
I have been reading about some of the hard-drive players and so far all of them use a rechargeable battery pack. How long does it take to recharge them? And how long do they usaully last? I am looking at the creative zen micro. I really despise having to buy another battery pack just to listen to the thing for a long time. How easily do hard-drive players skip? I would be using it to mow with, is there some sort of case that I could use?

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