Dry aid kits create a low ambient humidity environment which causes the cell to lose water. Assuming that when the aid was in use, no significant loss or gain of water from the cell has occurred, putting your battery in a dry aid kit will dry out the cell and shorten battery life. This difference in life would be most noticeable if your typical service life is more than 10 days. A dry aid kit may be beneficial for your battery, however, if you normally use your aid in a high humidity environment. The drying that occurs in the dry kit can counteract any excess water intake due to the humid environment that can shorten battery life.