I'm perfectly willing to write to about this. Is the low-battery notification located in the same area as these other notifications, i.e., the Twitter and Facebook notifications along with the Do Not Disturb feature? I even tried lowering my display brightness to 0 percent, as recommended by Apple but still no dice. Just this morning as I was checking my personal email account, I got a Twitter notification which was spoken.

I have a 13-inch Mac Book and our systems appear to differ slightly in the position of things, but I'm still able to navigate hers with no problem. I noticed that her low-battery notification doesn't appear to be read out by Vo either. So I was designated the trainer for my sister I think until her in-store training. My sister said the guy helping them was very good, but just as with my experience the store was rather busy and therefore hard to hear Voiceover. Nobody else in our area knows Voiceover, aside from the good folks at our Apple store. A sister of mine got an 11-inch Mac Book Air just last week, and she is also a Voiceover user. I'm revisiting this topic because I've done a little bit of further investigation into this.

Battery notifier app