Does one size fit all? The short answer is - No.
Different types and styles of hearing aids require different battery sizes. When you purchase hearing aids your dispenser will show you how to insert the battery correctly and also inform you of the correct size. Battery sizes have a number and a corresponding color tab.
Moisture is the enemy of electronics and a hearing aid is an electronic device. Moisture from humidity, sweat and dampness can damage your hearing aids. It reduces battery life and if left unchecked will cause corrosion and reduce the life of your investment.
It is almost impossible to avoid all moisture so hearing aids will inevitably be exposed to it. The best way to minimize the impact is to use some sort of dehumidifier specifically designed for use with hearing aids. There are many types available on the market and most work on the same basic principle; silica gel absorbs moisture.
If you own hearing aids it is recommended that every night you follow this routine: remove your hearing aids, gently wipe them with a clean, dry tissue, remove the batteries and place the hearing aids into a hearing aid dehumidifier overnight. By doing this daily you should dramatically reduce the incidence of annoying repairs and extend the life of the hearing aids.
The life expectancy of a hearing aid battery can vary greatly. It is dependent on a number of factors including: the brand of battery, how it has been stored, its size, the type of hearing aid and the settings of that hearing aid. This makes it sometimes difficult to determine whether a battery is about ready to be changed or not.
A hearing aid battery tester is very useful if your hearing aid is not working and you need to troubleshoot the problem.