After testing these Rayovac Size 312 batteries in my daily hearing aid use for months, I'm thoroughly impressed. The 60-count pack lasts me nearly a year, and at this price point, it's like getting 7+ drugstore packs for the cost of one!

The zinc-air design delivers consistent power - my aids maintain crystal clear sound for about 5 days per battery (your mileage may vary based on usage). Unlike some competitors, I've never encountered a dud in multiple packages - every single cell has worked flawlessly.

What really stands out is the packaging convenience. The simple plastic wrap (no frustrating childproof containers!) makes battery changes quick and easy - crucial for elderly users or those with dexterity challenges. Though one reviewer mentioned packaging difficulties, I found them easier to open than most alternatives.

The environmental focus is a nice bonus too - mercury-free with responsible manufacturing. Performance-wise, they outlasted Power One batteries in my tests by nearly 26 hours on average!

Two minor drawbacks: voltage measurements showed slight inconsistencies in one batch (1.37v vs advertised 1.45v), and recent packaging changed from 8 to 6 batteries per sleeve due to inflation. But given the overall value and reliability, these remain my top recommendation for hearing aid users.