Battery life depends on the battery type, hearing aid power requirements, and how often you use it.
Hearing Aid batteries are produced in 5 sizes. These sizes are: 5, 10, 13, 312, and 675.
The most popular is size 312 which normally lasts between 5 and 10 days. While the smallest size battery currently available is size 5, it's hardly ever used these days. This battery is usually used when even a #10 battery is too large to be put into the hearing aid.
When you get your hearing aid, ask your doctor which color corresponds to the correct hearing aid battery.
Key word: hearing aid batteries