Nancy, it is unnecessary to leave the battery attached to the charger all the time in between uses. A good practice it to store the battery in a 30-50% charged condition in a temperature controlled, moisture-free location off the charger. The battery is equipped with a self-maintenance function that will reduce the charge to 30% after more than a month of storage. This will save you electricity as your charger won't be plugged in and your battery life will be extended. Please let us know if you have any other questions.