Have a question about handheld systems like the DS, and PSP

Are there stores where you can buy batteries for handhelds systems like the DS, the PSP, the 3DS and PS Vita? Or can you only get batteries on some online site? Cause I have the DS and PSP for a long time (although I haven't really actually played either of them in a real long time cause I mostly play the PS3, and sometimes PS2, maybe the Wii once in a while) and I can't help but feel one of these days, I'm may have to change the batteries on the PSP or DS and other handheld systems.

What? You can't buy batteries from some store like Gamestop or Walmart or any other stores??

In Nintendo's case, I think you have to buy them directly from Nintendo. Check their website.

So overall, they don't sell batteries for DS and PSP in some store like Gamestop, or Walmart or any other stores?