08-22-2016 01:44 PM
when a company says the battery is not replaceable it means opening the device will void warranty and they do not sell the batteries. sandisk's own user manual states the battery is not replaceable. you may be able to solder a replacement battery to the board if you can find one and if you can there is no guarantee it will work.
08-22-2016 02:39 PM
If I recall correctly, I found 1 or 2 replacement batteries at aliexpress.com, at a good pricing; eBay may have listings as well. Of course, as noted above, you--the user--need to do the replacement work.
08-22-2016 03:08 PM
Replacement battery, via eBay.com: http://www.ebay.com/itm/Original-Sandisk-Sansa-Clip-Zip-4gb-8gb-Replacement-Battery-Pack-303038P-/40...
(Same item/seller also is listed at eBay.de: http://www.ebay.de/itm/Original-Sandisk-Sansa-Clip-Zip-4gb-8gb-Replacement-Battery-Pack-303038P-/401...)
Unfortunately, not inexpensive. As the seller notes, there are three solder points to contend with (and tiny little wires).