There are two decisions manufacturers take when designing new portable gadgets that make little sense to consumers. The first is a continued push to make devices thinner rather than increasing the size of the battery. The second is not allowing the battery to be removed and replaced when it wears out.
Those have been complaints of both smartphones and laptops, but it looks as though Nintendo made the same decision with the forthcoming Nintendo Switch.
As Engadget reports, a new FCC filing contains reference to the battery used to power the Switch handheld, and it clearly states, "the user can't remove the battery" on page 4 of the SAR Test Report, which is the results of testing the RF exposure characteristics of a device.
You may remember that the Wii U GamePad contained a battery that was removable. Nintendo even offered a larger battery pack for it if you so desired, but for the Switch, that seems to be out. However, it's important to point out that the FCC is reviewing a Switch prototype and not the final unit, but it seems unlikely a non-removable battery will become removable at this stage.
A non-removable battery doesn't mean it can't be changed, it just requires more effort and sourcing a replacement could be problematic. How difficult it turns out to be depends on how much glue is used to seal the Switch, and whether Nintendo opted to seal the unit at the front (meaning opening it risks breaking the screen) or the back.
Nintendo is revealing more details about the Switch on January 12. If we get some high quality images or video of the final handheld, it should be easy to tell whether the case can be opened and the battery removed.