I use the 312 mself and these # 10's are for my daughter.. I purchased them so she could give them a try. My bet is she will use nothing else ever again.
I have used Rayovac hearing aid batteries for several years and have not found any other brand that lasts any longer as a rule. However when I received some Rayovac packages at my local drug store last fall that had a short service span, I sought a source for batteries less apt to have been aging in the retail inventory and delivery chain. I was pleased to find that these could be purchased directly from the manufacturer. I was also pleased to see them marked: "BEST IF USED BY 03/18" which is a later date than any I have purchased in a store.
Longest-lasting and most reliable batteries I have used
on August 27, 2014
Posted by: Northside22
from Richmond, VA, USA
Gender:Male
Verified Purchase:Yes
After using a variety of domestic and foreign-made products, I happened to buy a pack of Rayovac batteries. I have been sold on Rayovac ever since. They outlast other batteries and are totally reliable, so much so that I can predict to the day and part of the day when I will need to replace them. And, both batteries in a set more often than not die within an hour or so of each other.