I’d never noticed the "don’t use Energizer" note on the smoke detector before. But sure enough, it’s still chirping.

So I went to look online for why, and found that auto-complete has some odd ideas of what smoke detectors need.

For the record: I didn’t find a satisfactory answer. A lot of talk about types of batteries based on power consistency and drop-off rates. You don’t want something that stays high-power longer, then quickly drops below the level needed to produce a low-battery alert. That makes sense. But specific brands? The consensus was split between specific brands having been rated in tests, or specific brands having deals with the smoke detector manufacturer.