Days in Inventory. The formula to calculate days in inventory is the number of days in the period divided by the inventory turnover ratio. This formula is used to determine how quickly a company is converting their inventory into sales.
How long do hearing aid batteries typically last? A standard hearing aid battery lasts anywhere from 3 to 22 days, depending on the hearing aid type, battery type and capacity, and the amount of hearing aid use. How do I know if I should change batteries? Change your batteries if sounds become distorted or you have to turn up the volume more than usual.
In an application like that, they could expect to see an OPTIMA battery last up to four years. However, in a more moderate climate, like San Diego, if someone might see four years out of a flooded battery, they could see up to eight out of an OPTIMA. How the batteries are used also impacts performance and lifespan.