Okay, so I've been using these Rayovac 312 batteries for my hearing aids for a while now. Here's the tea:

First off, the price is unbeatable. Like, why would I pay the same amount for 8 batteries at CVS when I can get 60 here? That's just math.

The performance is solid too. Most batteries work perfectly fine, and I rarely get duds. My hearing aids usually last about 4-5 days per battery, which is pretty standard.

BUT... I did have one weird experience recently. Opened a fresh pack, and my hearing aids immediately said 'low battery.' Checked the voltage – it was lower than it should be. Super annoying since the expiration date was years away.

Packaging could be better too. My elderly mom struggles with opening them (bring back the pull tabs please!). Though some reviewers love that they're not in childproof containers – pick your struggle I guess.

Overall? Still my go-to for value and reliability... but maybe check each battery's voltage when you get them just in case!