I recently purchased a Galaxy Player 4 which I use (among other things) for both on-the-go eReading and listening to audio-books.
As I said in my
short review of the Galaxy Player 4, one of the things that caused me to choose it over both the iPod and Galaxy Player 5 was the fact that the Galaxy Player 4 has a battery that is
readily available at low cost and easily swappable (you just unsnap the rear cover and pop in the replacement like many cell phones).
On my Sony PRS-650 the battery is
also available, though the replacement procedure involves partially disassembling the device.
Though battery replacement on the Sony 650 is a much bigger bother than my Galaxy Player (and my new Sony PRS-T1 is even worse because it requires soldering the battery leads instead of just plugging a small micro-connector), at least both batteries ARE at least technically user replaceable if you know what you are doing.
Though I would NOT have purchased either device if the battery was totally non-replaceable, the whole issue is somewhat less of a concern with an eInk device due to the lower number of battery cycles involved.
For example, with very active use, I rarely have to charge one of the Sony's more than
once a week. Compare this to the Galaxy Player 4 which, due to the LCD screen, requires recharging the battery fully
every day.
This means that, with a lithium-ion pack good for roughly 400 full charge-discharge cycles, a single battery pack would be good for only a little over a year on my Galaxy Player, but for more than 7 years on my Sony eInk devices.
Having my new Galaxy Player turn into iGarbage after only a little more than a year (like most Apple products with non-replaceable batteries) was not acceptable to me, but 7 years or more may well be the life of the product.
Sorry to detour into politics, but I think this is one case where a little 'over regulation' might actually be a good idea. The Governments in Europe and the U.S.A. should hit manufactures like Apple that irresponsibly manufacture land-fill-bait-products (like Apple's whole iTrash product line) with an up-front waste-disposable and carbon-use tax equal to 25% of the initial sale price on ANY product that does not include either a 5 year non-prorated free battery replacement guarantee, or alternately, provide for an easily replaceable, drop-in user replaceable battery. (like my Galaxy Player 4)
If they did that, my guess is that you would see drop-in replaceable batteries on ALL tablets and smart-phones within a few months.