Right, it is the Insignia "tabletop" with AC cord or can use 4 AAs. Best Buy had it for about $50 (currently $60). They may still have it but maybe not in every store.
The one I have (bought in 2009, just before WBCN was flipped to WWBX) had only an internal rechargeable battery. I bought it in July of 2009 at Best Buy. In the summer time when I run outside, not at a gym, I'll test it to see what I can pick up. Last summer, I noticed a drop of original formats on HD-2/3, from when I first bought the device. Gone are 70s only (WROR?), 80s only (then-WBMX, now WWBX), Local Music only (WBOS), Blues (WZLX), Irish Music (then-WTKK, now WBQT), Independent Rock (then WBCN, now WWBX), Live Rock (then WAAF, now WKVB). I see about 10 years ago as near the peak of content in Boston. I identify the Entercom/CBS merger as more of the decline of original content.
There's original content now (not imported from out of market or an AM station), but far from what it used to be. Old FMs that were moved to HD only stations came and went (WODS and WBCN). Formats like Evolution came and went. Original remaining is limited to the LGBTQ+ dance station, BiN, Hub Cast, and WAAF if we're account for all the stations that were dropped recently. Am I missing any?
That's my observation. It's becoming limited. I remember arguing in favor of HD Radio over Satellite, citing the unique stations in Boston alone, back in 2009. As the landscape of formats change, I find myself on the other side of that debate. As I write this, I'm listening to satellite's new rock channel. I struggle to find a station anywhere that is mostly new rock with only some 90s/2000s songs thrown in. On most modern rock FM stations such as WGIR-FM or the HD version of WAAF, new is relegated to new songs from veteran bands/musicians. I will hear Ozzy's new music, but I wouldn't hear Ice Nine Kills, for example. Satellite has the ability to play less known bands, due to the subscription model over the advertising model.